Duel Circuit Break master cylinder spacer

I always knew I wanted to upgrade my single break master cylinder to a duel circuit system but was always put off at the price of the CPS kit required to do this, when I first started looking they were £85 and at a Volks World show I saw a kit for £130 so  thought I better get the kit from the cheapest stall I could find this was for £119  

 

For what you get this is very over priced, so I never broke into the kit thinking I may be able to put it together cheaper myself. I recently found other parts shops are now making there own less expensive version of this kit.

 

Having a bit of time while the van was being painted I dug out the duel circuit master cylinder I got from my recent batch of parts purchase, and ordered from e-bay three 90mm x 20mm thick billet aluminium bar for £11 posted. 

 

A set of dividers marked the ruff centre and using an optical punch that uses a Perspex shaft with a cross on the end, once aliened the base is held in position and the shaft is replaced with the punch that once hit provides a very accurate centre punch. 



Once I'd swapped the jaws in the lathe chuck to hold a larger piece I centred the billet, drilled a pilot hole then bored it straight through. The CSP spacer has a step I think this is to help keep the gator on

 

I cut the hole tight enough to seat against the o ring on the face of the master cylinder

 

Whilst in the chuck I marked the position for the bolt holes.

 

Once marked I checked there alignment with the master cylinder and also marked the outer profile of the mating surface.

 I cut the profile out on my chop saw which is not very accurate, because the table moves when cutting, this led me to under cut the profile a bit. I cleaned up my mistake and rounded the corners with a hand file.

 

Clamping my grinder the bench with quick clamps I fitted a buffing wheel a tried my first bit of polishing. This was prity straight forward I just had to keep the work under the centre of the wheel and work off the trailing edge so it would not catch the work.

 

A quick trial assembly

 

I had to try in on the van once I had it back from paint.

 

My next query was with the rubber gaiter provided in the CSP kit has a lip to sit in a groove like the original one but because the duel master cylinder is for fitting onto a servo it does not need a boot.

I will look for other boots or cut a groove in my MC so it stays on. 

Rear shock mounting for 944 IRS conversion pt5

This will be my fourth attempt at welding these supports so I should be able to get it right by now. I folded up the piece needed to provide the space for the clearance of the shock when it swings forward and backwards.I used the bench to make sure the two pieces were straight with each other. So as I welded the two parts together I set the bench alight, and didn't notice until I couldn't see the weld through the smoke and had to lift up my welding mask.

With the clearance piece welded in and a few more trial fits I then reamed the shock mount holes with an adjustable reamer and used one of the bushes as a guide. This didn't really work as well as I hoped. The reamer wobbled because it was such a large diameter for using by hand and this caused it to cut a jagged hole. I should have put it in a pillar drill. The hole still came out with a snug fit for the bushes just not as clean as I had hoped.

A few more trial fits and I was able to mark where the swing arm wanted to foul the edge of the support. The clearance issue was sorted using a huge mallet, steel dolly and some old decking that used to cover up the fish pond. Yup, just like Thor.

This time I tried to bend the radius where the two parts met before it was welded in place. but I ended up bending the two edges at different heights and still needed to place a couple of cuts to relieve the bends. I later dressed (hit with a large mallet) the ends so they aligned once the support was welded in place

A picture before assemble because I got a bit snap happy with the camera.

This is the support painted, assembled and checked for the shock clearance at the correct height for the top shock mount hole and the supports squareness with the other side.

The A arm and shock was then removed and the support welded into place with a seam weld either side at the top and a seam weld inside and out at the bottom but finished flush to try and make it look like I'm good at welding. I may add another weld inside at the top as the skin it's welded to is thinner on the inside of the chassis than the outer where the original mount was welded. I have seen a shock mount  welded on the inside rip away from the chassis, so I will have to consider this.

I had one last bush to trim to size, so I used my new toy which took 5 minutes..

I could try and sort out an anti roll bar but I'll recondition the hand brake shoes first, sort the hand brake cable out, work out what length drive shafts I'll need and see if the wheels are straight and square with each other first.

Heres the parts I've made or had made to get this lot to all fit together.

With a couple of used tyres slung on the wheels the van is finally on the ground with its new rear end. This has taken a lot of work, too much time, mental skills and help from a few friends but is now finished (nearly), so up yours to who ever told me it could not be done.

Rear Shock Mounting for 944 IRS conversion Pt4

With the left shock mount welded in place I just needed to tidy up the excess material from the new section sticking out the bottom.

I sorted this out by cutting a bending block to the radius I wanted clamped it to the van then started hitting very hard with a really big hammer, this didn't quite work as I had hoped.

So I had to make a couple of strategic cuts with the angle grinder then start hitting it again really hard.

With the help of the gas torch I finally managed the bend I needed

Then welded up the gaps

Ground the welds down then hid the welding with some red oxide paint

With one side done I get to start on the other side.

With a little less disregard than the first time I cut the van up. I dug out the electric saw I had for cutting my hedge down, It took me 2 min to pull the support out.

Then cleaned up the surface of the spot welds so I could see where to drill them off.

With the old support out the way I can mark the cutting angles I need.

to be continued.......

Rear Shock Mount fitting for 944 IRS conversion Pt 3

I was able to visits my uncles workshop and turn down a couple of brass bushes to fit inside the top mount bearing this is because the bolts I'm using is 12mm and the bearing hole is 15mm. I also found out later I used the wrong cutting bit. that's a whole different world.

I also faced of one of the other bushes to give me the offset position I needed for the top mount. when at full extension the shock is vertical and the top mount collar just sits off the forward face, when compressed the shock swings back and because of the off set now sits clear of the back face.

Now that I'm happy with the top and bottom shock mounts I cat fit the new section. I removed the spring plate and A arm then clamped the lower part of the section with panel clamps and adjusted the top till it sat square with a bit of persuasion and also lined up with my previous marking of the highest and lowest position for the mount bolt.

With the upside down, on my back, stuck under the van, not able to move welding done and the spring plate and A arm fitted you can now see the final result.

I'll tidy the lower point and form a radius and then there's just the other side to do, just hope it does not take me 6 month's.

Rear Shock mount Fitting for 944 IRS conversion Pt 2

After messing up the width of the last top hat section I attempted to bend up some more, this took another trip to the metal shop and several more attempts at fabrication, all this just to get the width 1 mm thinner

With the old cardboard template from my first attempt I dug out from the pile of scrap metal, I marked out the angles needed for the bend with a small hole drilled in the corner to relieve the bend. A couple of blocks, a large clamp, 2 litres of coke and Thors' Hammer allowed me to make the bend.

A trial fit just once, twice or seven times allowed me to adjust the angles of the cuts slightly so it would fit. This meant climbing in and out of my engine bay on my hands and knees each time. I like my van to know it's the Boss in our relationship.

A couple of tack welds on the bend line while the section was clamped to the chassis rail and then it was removed to be seam welded and then attacked with the grinder to hide the bodgy welding.

I cut up some of the other section I'd made so that I could see if it was worth fitting these U sections inside the top mount area to strengthen the support but it would have been to awkward to spot or mig weld these in place and they would have reduced the clearance inside the top shock mount even more that it already is.

I also bought some brass oiled bushes, one top hat, two for clamping either side of the shock mount bearing and a third that can turn down to the required length to get the correct position for the top mount. The shock mount hole is 1/2" (12.7mm) or 15mm (with the supplied spacer removed) and the brass bushes could not be supplied in either internal size, so I went for 12mm internal with 18mm outer. This is the diametre of the regular shock mount bolts for a van.

With the position of the top mount holes calculated from the nominal extension and retraction of the shock taking into account the full range of the A arm and the compression of the bump stop. I then ignored that and drilled a couple of holes where I thought looked good. Fitted a 1/2" bolt from a Creative Engineering mount kit,  some bushes from a Demon Tweeks mount kit and a few washers allowed me to adjust the position of the mount forward and back to get the best position for inside clearance and shocks angle. 

This also meant cutting the chunk out of the section so the shock would tilt back as the wheel moved up. A few ideas were passed around by my design team as to how to overcome this weak spot and the best idea that I/we could come up with was to cover the shock keeping the existing angles. So I raided the cornflake packet again to work out what shape I'd need.

I also needed to clear the back of the section where the A arm moved up and rubbed. I cleared this originally by cutting it out with the grinder, This time I heated the section up and grabbed Thor's Hammer again to beat the whatever out of it. The blocks helped keep inline what needed to stay straight and I got to let all my aggression out. 

With most of the fabrication now sorted I can concentrate on getting the holes drilled for the top mount bushes. The price of a 18mm hss drill bit was £14.95 and too much for just 4 holes so I reluctantly borrowed a Christmas Tree hole cutter and attempted to drill a pair of parallel holes in an unsupported springy piece of folded steel, the use of the pillar drill did help.

To get the second hole drilled in the correct position I fitted the bush into the first 18mm hole then clamped it in the pillar drill vice, by slotting a 12mm drill into the bush and poking it out the other side I  was able to line up the tip of the hole cutter with the tip of the 12mm drill bit. I drilled away and it still looked a bit off. 

I just need to turn down the bushes to the correct length and I can then weld this side to the van and then do it all again for the other side. Whoop whoop.