No pictures in this update. The Sprinter went in for the re-test this morning and passed.
As expected there was an advisory issued on one of the brake pipes (this was highlighted during the initial test as well). I plan on replacing this and any other pipes needed when I get it up to Milton Keynes for a full service. (Peter has a brake pipe flaring tool).
That's all for today folks!!
Friday, 14 August 2009
Saturday, 8 August 2009
Sprinter 412D twin wheel rear brake overhaul
Here is a blow-by-blow, picture-by-picture account of the overhaul of the rear brakes on my 1998 Mercedes 412D twin wheel Sprinter.
I ordered the parts from the local motor factors that we normally use who are able to look up the vehicle based on registration number. Turns out their system is flawed and the parts they supplied were for the single wheel Sprinters. I then went to another supplier, ditto, same thing. I decided to stop wasting my time and went straight to Mercedes and walked out with rights parts 10 minutes after walking in. Strangely while my arms were loaded down with 2 really heavy discs and a set of pads, my wallet felt lighter by the same amount.
Please Note/Disclaimer: This article is a description of the work I did to my vehicle and in no way constitutes advice to work on your own. If you are not an experienced mechanic then please get an experienced mechanic to work on your vehicle for you. No liability can be accepted for anyone attempted to replicate anything shown on this blog.
This job was started by chocking the vehicle, jacking it up, putting some stands under and removing the rear wheels (one side at a time). The handbrake was released and cable cam adjuster (underneath in the center of the vehicle slackened off.
I proceeded to remove the 'wheel carrier' (for want of a better name), the caliper and the caliper bracket. The wheel carrier is removed by removing 6 19mm bolts located around the center of hub. The bolts came loose easily, but I needed to 'tap' the carrier with a 4 pound hammer to get it to pop off.
The caliper comes off the bracket by removing two 13mm bolts from the sliders which need to be held with a 17mm spanner. I tied the caliper up and rested it on the leafspring to ensure flexi hose didn't twist or become damaged. This came off easily. The old pads can be removed at this time.
The caliper bracket is held on with two 19mm bolts. The lower one came loose after only about 30 mins of fighting with it. This involved copious amounts of easing fluid (I didn't mind contaminating anything in brakes as all were being replaced). The upper one onf the other hand required copious spraying, lots of swearing, heaving and pulling on a long cracker bar. As I had started the one side the night before, it benefitted from having been sprayed some hours before and then soaking. For the other side I didn't want to wait 12 hours so after much effort I eneded up heating it with a blow torch. (CAREFULLY: I made sure I had a fire extinguisher, and directly the blow torch only at the bracket which wasn't near any seals or brake parts - the caliper already have been safely moved out of the way).
For each side I spent as much time on the top caliper bracket bolt as on the rest of the stripdown put together.
I then proceeded to remove the disc. First ensuring the vehicle was out of gear so the disc could rotate. This allowed me to slacken off the adjustment on the shoes to ensure they weren't binding on the drum section. As the drums wear and dirt and rust builds up a slight ridge is formed on the rear which can grip the shoes. Even with the adjuster totally slackened off and being able to see that the shoes were free (see pictures), it still took a lot of 'tapping' with the 4lb hammer to get the disc off as it has a reasonably close fit on the hub.
On removal of the disc I was able to properly inspect and then remove the handbrake shoes. I took pictures of these in situ in order to ensure that I didn't get the springs, etc confused but they are all pretty straightforward.
As can be seen from the pictures the shoes were totally down to the metal and had been eating away at the drum section of the disc.
In preparation for the re-assembly I stripped down the adjuster. It pulls apart and the toothed section can be unscrewed. I then coated all the working parts with anti-seize compound and worked them back and forth onre-assembly to ensure that the fully working range was free. I also unpacked the new shoes at this point and took a 'new vs old' picture.
Re-assembly of the brake system then began by fitting the new shoes, this is simply a 'Haynes manual' approach of reversing the disassembly procedure (BTW: I didn't have a manual so tackled this using common sense and the advise of the friend on specifics, but I do have extensive experience of working on cars as a hobby). Make sure that the adjuster is wound back fully.
To assist with hooking the springs in I took an old coat hanger and fashioned a hook with it (a trick my father used in the lifetime he spent running a commercial garage).
Next up the new disc went on. This was first cleaned with some 'brake and clutch' cleaner to ensure it wasn't covered in oil/grease. Having said that I found these (Mercedes) discs to appear to be a lot cleaner than the motor factor supplied discs on which you tend to detect the protective layer. Mercedes supply these in a protective plastic bag inside the box.
Before bolting on the wheel carrier I cleaned it up with a wire brush. This was then bolted back using thread locking compound on the 6 19mm bolts.
In preparation for refitting the caliper bracket, I stripped the sliders down. These can be prone to siezing (more so on some vehicles than others) if not serviced properly. It is pretty simply to do, they simply pull out and the dust cover pulls off. I cleaned them off with an old rag and then coated liberally with anti-sieze compound. Re-assembly followed during which I worked them back and forth to ensure that the anti-sieze was spread evenly inside and that they were functional. I also cleaned the heads of the sliders to ensure that spanner would fit on any of the faces.
I re-fitted the bracket to the hub with the 2 19mm bolts and some thread locking compound (don't want brake parts coming loose). The area of the caliper bracket where the pads slide was also cleaned as even small amounts of build in these areas can cause the pads to stick which can reduce braking efficiency dramatically.
Before refitting the caliper and the new pads, the pistons needed to be pushed back. Luckily they weren't extended too far as the pads on the vehicle were only about 5-10% worn. I don't know why they didn't replace the discs when they puts these pads on as they can't have been on for very long (especially as this was an ambulance). I could have re-used the old pads, but will rather put them on the shelf for the next time as I think new discs deserve new pads.
On advice from my friend Peter, I attached a bleed hose to the bleed nipple and cracked that open while pushing the pistons back with a clamp. This would ensure that the old fluid escapes rather than being push back up the line into the ABS system.
The picture below also shows where the new sensor wire plugs into a recptor on the caliper (They didn't bother with the wires during the last pad replacement). You should however fit the sensor wire to the pad first (I learnt this the hard way).
The pads were then slid into place and the caliper remounted using the 13mm bolts. As I had bought the pads from Mercedes thay came with new bolts that have a thread compound pre-applied. If you are re-using the old bolts, make sure you use some thread locking compound on these safety critical parts. The sensor wire was fed through the hole in the caliper and plugged in.
The final step before refitting the wheels and repeating the procedure on the other side was to adjust the handbrake shoes. This was done by turning the disc to align the adjustment hole with the 'geared' adjuster wheel (just visible in the picture).
The adjuster was wound out using a screw driver until the handbrake shoes held the disc. It was then freed off again until just free. Remember that I had slackened off the cable adjustment under the vehicle prior to this. Once both wheels had been completed I adjusted the cable adjuster under the vehicle (picture below - this is done by releasing the 13mm bolt, twisting the cam - using an allen spanner - and the tightening the 13mm bolt) until the handbrake lever took with about 5 clicks. I also sprayed the cable adjuster liberrally with anti-sieze spray. I intend to remove and service this at the next service, but don't believe this needs to be done for the MOT re-test.
I ordered the parts from the local motor factors that we normally use who are able to look up the vehicle based on registration number. Turns out their system is flawed and the parts they supplied were for the single wheel Sprinters. I then went to another supplier, ditto, same thing. I decided to stop wasting my time and went straight to Mercedes and walked out with rights parts 10 minutes after walking in. Strangely while my arms were loaded down with 2 really heavy discs and a set of pads, my wallet felt lighter by the same amount.
Please Note/Disclaimer: This article is a description of the work I did to my vehicle and in no way constitutes advice to work on your own. If you are not an experienced mechanic then please get an experienced mechanic to work on your vehicle for you. No liability can be accepted for anyone attempted to replicate anything shown on this blog.
This job was started by chocking the vehicle, jacking it up, putting some stands under and removing the rear wheels (one side at a time). The handbrake was released and cable cam adjuster (underneath in the center of the vehicle slackened off.
I proceeded to remove the 'wheel carrier' (for want of a better name), the caliper and the caliper bracket. The wheel carrier is removed by removing 6 19mm bolts located around the center of hub. The bolts came loose easily, but I needed to 'tap' the carrier with a 4 pound hammer to get it to pop off.
The caliper comes off the bracket by removing two 13mm bolts from the sliders which need to be held with a 17mm spanner. I tied the caliper up and rested it on the leafspring to ensure flexi hose didn't twist or become damaged. This came off easily. The old pads can be removed at this time.
The caliper bracket is held on with two 19mm bolts. The lower one came loose after only about 30 mins of fighting with it. This involved copious amounts of easing fluid (I didn't mind contaminating anything in brakes as all were being replaced). The upper one onf the other hand required copious spraying, lots of swearing, heaving and pulling on a long cracker bar. As I had started the one side the night before, it benefitted from having been sprayed some hours before and then soaking. For the other side I didn't want to wait 12 hours so after much effort I eneded up heating it with a blow torch. (CAREFULLY: I made sure I had a fire extinguisher, and directly the blow torch only at the bracket which wasn't near any seals or brake parts - the caliper already have been safely moved out of the way).
For each side I spent as much time on the top caliper bracket bolt as on the rest of the stripdown put together.
I then proceeded to remove the disc. First ensuring the vehicle was out of gear so the disc could rotate. This allowed me to slacken off the adjustment on the shoes to ensure they weren't binding on the drum section. As the drums wear and dirt and rust builds up a slight ridge is formed on the rear which can grip the shoes. Even with the adjuster totally slackened off and being able to see that the shoes were free (see pictures), it still took a lot of 'tapping' with the 4lb hammer to get the disc off as it has a reasonably close fit on the hub.
On removal of the disc I was able to properly inspect and then remove the handbrake shoes. I took pictures of these in situ in order to ensure that I didn't get the springs, etc confused but they are all pretty straightforward.
As can be seen from the pictures the shoes were totally down to the metal and had been eating away at the drum section of the disc.
In preparation for the re-assembly I stripped down the adjuster. It pulls apart and the toothed section can be unscrewed. I then coated all the working parts with anti-seize compound and worked them back and forth onre-assembly to ensure that the fully working range was free. I also unpacked the new shoes at this point and took a 'new vs old' picture.
Re-assembly of the brake system then began by fitting the new shoes, this is simply a 'Haynes manual' approach of reversing the disassembly procedure (BTW: I didn't have a manual so tackled this using common sense and the advise of the friend on specifics, but I do have extensive experience of working on cars as a hobby). Make sure that the adjuster is wound back fully.
To assist with hooking the springs in I took an old coat hanger and fashioned a hook with it (a trick my father used in the lifetime he spent running a commercial garage).
Next up the new disc went on. This was first cleaned with some 'brake and clutch' cleaner to ensure it wasn't covered in oil/grease. Having said that I found these (Mercedes) discs to appear to be a lot cleaner than the motor factor supplied discs on which you tend to detect the protective layer. Mercedes supply these in a protective plastic bag inside the box.
Before bolting on the wheel carrier I cleaned it up with a wire brush. This was then bolted back using thread locking compound on the 6 19mm bolts.
In preparation for refitting the caliper bracket, I stripped the sliders down. These can be prone to siezing (more so on some vehicles than others) if not serviced properly. It is pretty simply to do, they simply pull out and the dust cover pulls off. I cleaned them off with an old rag and then coated liberally with anti-sieze compound. Re-assembly followed during which I worked them back and forth to ensure that the anti-sieze was spread evenly inside and that they were functional. I also cleaned the heads of the sliders to ensure that spanner would fit on any of the faces.
I re-fitted the bracket to the hub with the 2 19mm bolts and some thread locking compound (don't want brake parts coming loose). The area of the caliper bracket where the pads slide was also cleaned as even small amounts of build in these areas can cause the pads to stick which can reduce braking efficiency dramatically.
Before refitting the caliper and the new pads, the pistons needed to be pushed back. Luckily they weren't extended too far as the pads on the vehicle were only about 5-10% worn. I don't know why they didn't replace the discs when they puts these pads on as they can't have been on for very long (especially as this was an ambulance). I could have re-used the old pads, but will rather put them on the shelf for the next time as I think new discs deserve new pads.
On advice from my friend Peter, I attached a bleed hose to the bleed nipple and cracked that open while pushing the pistons back with a clamp. This would ensure that the old fluid escapes rather than being push back up the line into the ABS system.
The picture below also shows where the new sensor wire plugs into a recptor on the caliper (They didn't bother with the wires during the last pad replacement). You should however fit the sensor wire to the pad first (I learnt this the hard way).
The pads were then slid into place and the caliper remounted using the 13mm bolts. As I had bought the pads from Mercedes thay came with new bolts that have a thread compound pre-applied. If you are re-using the old bolts, make sure you use some thread locking compound on these safety critical parts. The sensor wire was fed through the hole in the caliper and plugged in.
The final step before refitting the wheels and repeating the procedure on the other side was to adjust the handbrake shoes. This was done by turning the disc to align the adjustment hole with the 'geared' adjuster wheel (just visible in the picture).
The adjuster was wound out using a screw driver until the handbrake shoes held the disc. It was then freed off again until just free. Remember that I had slackened off the cable adjustment under the vehicle prior to this. Once both wheels had been completed I adjusted the cable adjuster under the vehicle (picture below - this is done by releasing the 13mm bolt, twisting the cam - using an allen spanner - and the tightening the 13mm bolt) until the handbrake lever took with about 5 clicks. I also sprayed the cable adjuster liberrally with anti-sieze spray. I intend to remove and service this at the next service, but don't believe this needs to be done for the MOT re-test.
Thursday, 6 August 2009
Camper Part 20: Poorly Patient.....
Short update today as not much news since the MOT.
As expected (but not hoped) the Sprinter failed the MOT. The worse issue was the rear brakes which failed on both the brakes and the handbrake. Apart from that the odd light was deemed faulty and the wipers not good enough. I had checked the lights the night before, but can't fault them on the rest.
Today Lorraine went and picked up the parts to do a complete rear brake overhaul, but I am taking it easy in the evenings as we have managed to book an alternate holiday for next week, so the pressure is off.
I don't want to slack off too much though as I want the van done for weekend trips. On Saturday I will be tackling the brakes, which hopefully leaves Sunday for the lights meaning that I can book it in for a re-test on Friday. (We're away from Monday to Thursday).
As expected (but not hoped) the Sprinter failed the MOT. The worse issue was the rear brakes which failed on both the brakes and the handbrake. Apart from that the odd light was deemed faulty and the wipers not good enough. I had checked the lights the night before, but can't fault them on the rest.
Today Lorraine went and picked up the parts to do a complete rear brake overhaul, but I am taking it easy in the evenings as we have managed to book an alternate holiday for next week, so the pressure is off.
I don't want to slack off too much though as I want the van done for weekend trips. On Saturday I will be tackling the brakes, which hopefully leaves Sunday for the lights meaning that I can book it in for a re-test on Friday. (We're away from Monday to Thursday).
Tuesday, 4 August 2009
Camper Part 19: MOT Ready or not here I come...
There hasn't been an update for a few days as I have been putting all my energy into getting ready for the MOT (annual road fitness test).
As the vehicle is undergoing a conversion to a 'Motor Caravan' it qualifies for an MOT Test instead of a Goods Vehicle Test. This however means that it must have the basics of a Motor Caravan, like beds and kitchen.
On the weekend I fitted the new dash plastics that I had bought on eBay which resulted in the moving of some of the switches fitted during the ambulance conversion.
This was followed by continuing with the kitchen units. As you know (if you've been following) I completed the carcasses before, so this weekend I cladded the sides in plywood. I also fitted the sink and cooker hob to their respective counter tops and fitted the sink one in place.
At the same time I did the remaining two walls of the bathroom and the bathroom roof. This also involved cutting the holes for the lights in the bathroom and feeding through the wiring. Next steps for the bathroom will be the waterproofing, cladding and then fitting up.
After work I ventured out again and fitted the cooker counter top in place. This was followed by installing the grill box & door as well as the cooker oven. The gas lines for these are connected at the back, but still need plumbing through the floor for connection to the flexi-hose with bottle connector. The long term goal is to fit an under vehicle gas tank.
I also installed the fridge under the sink, but before this drilled the holes for the water supply and waste pipes in the floor and fed the pipes through. I still need to fit the external connections and pump, but didn't relish working on my back on cold concrete at 9:30pm so left that for another day.
As the finishing touch of the day, the passenger seat went back in (it had been removed in order to work on the auxilliary battery) and the cushions for the beds were fitted.
All through this time my wife was helping by clearing out all the accumulated tools and fittings that had migrated into the lockers in the vehicle during the build.
The pictures today aren't great as they were taken in the dark with a mobile phone, but you can get a sense of more completeness...
As the vehicle is undergoing a conversion to a 'Motor Caravan' it qualifies for an MOT Test instead of a Goods Vehicle Test. This however means that it must have the basics of a Motor Caravan, like beds and kitchen.
On the weekend I fitted the new dash plastics that I had bought on eBay which resulted in the moving of some of the switches fitted during the ambulance conversion.
This was followed by continuing with the kitchen units. As you know (if you've been following) I completed the carcasses before, so this weekend I cladded the sides in plywood. I also fitted the sink and cooker hob to their respective counter tops and fitted the sink one in place.
At the same time I did the remaining two walls of the bathroom and the bathroom roof. This also involved cutting the holes for the lights in the bathroom and feeding through the wiring. Next steps for the bathroom will be the waterproofing, cladding and then fitting up.
After work I ventured out again and fitted the cooker counter top in place. This was followed by installing the grill box & door as well as the cooker oven. The gas lines for these are connected at the back, but still need plumbing through the floor for connection to the flexi-hose with bottle connector. The long term goal is to fit an under vehicle gas tank.
I also installed the fridge under the sink, but before this drilled the holes for the water supply and waste pipes in the floor and fed the pipes through. I still need to fit the external connections and pump, but didn't relish working on my back on cold concrete at 9:30pm so left that for another day.
As the finishing touch of the day, the passenger seat went back in (it had been removed in order to work on the auxilliary battery) and the cushions for the beds were fitted.
All through this time my wife was helping by clearing out all the accumulated tools and fittings that had migrated into the lockers in the vehicle during the build.
The pictures today aren't great as they were taken in the dark with a mobile phone, but you can get a sense of more completeness...
Monday, 27 July 2009
Camper Part 18: Kitchen Carcasses Complete
As promised in yesterday's installment I got on with the final kitchen unit carcass today.
Having done the major cutting last night, tonight I trimmed the angles on the rear legs for where they meet the roof and assembled the whole lot. I also fitted it, including fixing to the floor, the wall and the cooker unit which it stands next to.
I had to move ond of the light fittings a bit as it will be partially obscured by the cupboard. It still is a bit due to a structural roof bracket preventing me from moving it further. This should be a problem however as the tube can still be changed easily.
Having now completed all the kitchen carcasses, next steps for the kitchen will be the counter tops. I will however be moving back to the bathroom in order to complete the side walls so all structures are in place.
After that, plumbing and electrics with paneling of the various carcasses being the last thing done in order to not have to remove them again (and not dirty them).
I also need to get on with checking the vehicle over for the MOT and booking that for next week.
Today's pictures:
Having done the major cutting last night, tonight I trimmed the angles on the rear legs for where they meet the roof and assembled the whole lot. I also fitted it, including fixing to the floor, the wall and the cooker unit which it stands next to.
I had to move ond of the light fittings a bit as it will be partially obscured by the cupboard. It still is a bit due to a structural roof bracket preventing me from moving it further. This should be a problem however as the tube can still be changed easily.
Having now completed all the kitchen carcasses, next steps for the kitchen will be the counter tops. I will however be moving back to the bathroom in order to complete the side walls so all structures are in place.
After that, plumbing and electrics with paneling of the various carcasses being the last thing done in order to not have to remove them again (and not dirty them).
I also need to get on with checking the vehicle over for the MOT and booking that for next week.
Today's pictures:
Sunday, 26 July 2009
Camper Part 17: Kitchen Kapers Kontinue
Following on from yesterday's successful completion of the bed boxes I started on the second kitchen unit this morning. This is the one which would house the cooker.
As I had stripped the cooker cupboard out of the caravan, I decided to use the front panel instead of trying to fabricate a new one of the same size. The main alteration was that the original panel had a step in it (the cooker was recessed backwards), which I removed. I also has to make it the same height as the sink unit. I achieved this by making up a skeletal carcass very similar to the one I made for the sink unit, but instead of making up a front panel I substituted the one out of the caravan, having trimmed it down.
If you're wondering about the mismatch in materials and hence the patchy look, don't. The entire unit will be covered in birch ply (as will the other kitchen unit). But I am finishing all the unit carcasses first as there is no need to use birch ply between the units. Excess weight and costs more than necessary for stuff that will be hidden anyway.
The final kitchen unit is a cupboard which will be attached to the side of the cooker unit. Not here I could have tried to make them as one and save a bit on the weight, but as I want the cupboard unit to be full (roof) height I figure it was better to make them seperate as they will be easier to install and remove if I need to (for sorting out the floor, etc).
This cupboard will be quite narrow (220 mm - same as the cupboard in the sink unit) as this allows the appropriate space for the passenger seat (and child's bed) to the front of it. It is intended only for kitchen use, so the narrowness should be fine as it will store things like cans, etc.
As can be seen from the pictures, I have already cut all the wood for this unit, so tomorrow night I can put it together. Well, I actually need to cut some more pieces for where the unit meets the roof, but due to the angles I decided to assemble the rest and then take measurements rather than attempt to figure it out and get them wrong. Unlike my usual approaches, I have been very carefull to measure twice cut once and have not made too many mistakes on this build so far (touch wood).
As I had stripped the cooker cupboard out of the caravan, I decided to use the front panel instead of trying to fabricate a new one of the same size. The main alteration was that the original panel had a step in it (the cooker was recessed backwards), which I removed. I also has to make it the same height as the sink unit. I achieved this by making up a skeletal carcass very similar to the one I made for the sink unit, but instead of making up a front panel I substituted the one out of the caravan, having trimmed it down.
If you're wondering about the mismatch in materials and hence the patchy look, don't. The entire unit will be covered in birch ply (as will the other kitchen unit). But I am finishing all the unit carcasses first as there is no need to use birch ply between the units. Excess weight and costs more than necessary for stuff that will be hidden anyway.
The final kitchen unit is a cupboard which will be attached to the side of the cooker unit. Not here I could have tried to make them as one and save a bit on the weight, but as I want the cupboard unit to be full (roof) height I figure it was better to make them seperate as they will be easier to install and remove if I need to (for sorting out the floor, etc).
This cupboard will be quite narrow (220 mm - same as the cupboard in the sink unit) as this allows the appropriate space for the passenger seat (and child's bed) to the front of it. It is intended only for kitchen use, so the narrowness should be fine as it will store things like cans, etc.
As can be seen from the pictures, I have already cut all the wood for this unit, so tomorrow night I can put it together. Well, I actually need to cut some more pieces for where the unit meets the roof, but due to the angles I decided to assemble the rest and then take measurements rather than attempt to figure it out and get them wrong. Unlike my usual approaches, I have been very carefull to measure twice cut once and have not made too many mistakes on this build so far (touch wood).
Saturday, 25 July 2009
Camper Part 16: Bedtime Bonanza
Last after work I started on the new side panels for the beds. In the caravan the bed boxes were fixed directly to the other cupboards so I needed to create new end panels.
This morning I continued with this, the fiddly bit was that due to the folding step I needed to modify the end and front panels to allow the step to get past. I also had to shorten the beds in order to fix.
The boxes have been completed, but will not be fixed into place until completion of the remaining units. As can be seen from the pictures, I reused most of the original units.
The contraption that you can see in the passenger side unit is the Eberspacher heater. I will possibly relocate this, but at the least move it so that it uses less space.
Tomorrow I hope to tackle the carcass for the second kitchen unit. This will house the cooker and also have a cupboard which runs up to the ceiling for kitchen storage.
This morning I continued with this, the fiddly bit was that due to the folding step I needed to modify the end and front panels to allow the step to get past. I also had to shorten the beds in order to fix.
The boxes have been completed, but will not be fixed into place until completion of the remaining units. As can be seen from the pictures, I reused most of the original units.
The contraption that you can see in the passenger side unit is the Eberspacher heater. I will possibly relocate this, but at the least move it so that it uses less space.
Tomorrow I hope to tackle the carcass for the second kitchen unit. This will house the cooker and also have a cupboard which runs up to the ceiling for kitchen storage.
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