I got my brake cylinder rebuilt over the weekend and it was indeed a PITA. I know I little chance of it working properly but sometimes it's about the journey, at least that's what I keep telling myself. The biggest challenges are compressing the springs at the same time you have to remove other parts and getting to the spring clips.

Getting the the first spring off is challenge in its self, I thought about quitting just getting it off. But eventually I was able to get a knife and get the spirolox off by starting it at one of the ends.

Even the 1st spring clip (circlip) was not easy, doesn't help that I have a cheap tool, but persistence wins. For the nylon washer I followed the other tips here and drilled two holes and used wood screws to pull it out.



Then next seal and washer were easy enough, but then the dreaded second spring clip! I actually got this one off much quicker then the first as I discovered I have a pair forceps with a much longer nose then my tool.

This all sounds quick writing it up, but I am already a few hours into this trying to figure this out.

With that I was able to remove the piston assembly. The next challenge is separating the piston links. Another very difficult "pull back the spring" maneuver. Two things really helped me here. One was that I used zip ties to compress the middle part of the spring. This really take a lot of tension off to be able get at the pin under the cap. Then I used a paper clip to hold back the cap from covering the pin. The pic I have here is after I got it off, but I think you can get the idea. The paper clip is holding against the end of the piston instead of the loop in the piston link.



Close up of the zip ties helping me out.


After that getting the seals off and back on are not too hard, but takes some effort. When I was ready to assemble the pistion again I drove the pin about 3/4 the way though with a vise and I was able to "hook" the link back in and drive the pin back though.

Putting the rest back together was pretty easy, just trying to keep everything clean was the harder part of it. Although the last part of getting that spirolox spring back on was not fun, but using the zip tie technique helped a lot.

I have some more before and after pics of the whole pedal\hydraulics box that I post when I get it all back together. But I wanted to get the MC stuff down while it was fresh in my head.

Again, I am not holding out a ton of hope that it will work when I get it all back on, but I can say that I did it.

Good job Jeff, nice trick with the zip ties on the spring!

good job

Most important part is the inside of the cylinder, if the surface is not as a mirror, then the seals will worn out very quickly. On my dual master cyl, both cylinders had the surface pitted and rusty, so I had to buy a new one.

You US people have a nice company there specialized in reboring the master cylinders and fitting a stainless steel tube inside

http://www.brakecylinder.com/spridgetbrakes.htm

nice photos!

how about posting your write up to the Library here? I am sure that others will benefit from your work, if you do so.


thx,
Norm

O.K. I have everything apart that needs to be right now, and heres my new problem. Obveously somebody has worked on this thing before. The inside of the cylinder looks great. I got myself a Haynes service manual, and according to the book the nylon guide bearing, the seal and then a washer. book shows 1 seal, but I pulled out 2 of them back to back. Does that sound right????

Paco,

You are absolutely correct about Sierra Specialty. From finished product to customer service, they are absolutely unsurpassed in every respect. I have been working with Joe for at least 14 years now and he is who I collaborated with to revive the availability of the 3/4" tandem master cylinders used in Spridgets with disc rakes from 1962 to 1966. Prior to around 2006-2007, only 7/8" MC's were readily available.

http://gerardsgarage.com/Garage/Tech/DbrakeUg.htm

I have all my master cylinders for all my British cars, sleeved by him. I would only correct you that they are done in brass, not stainless. Brass is actually a better solution and he addresses that issue on the web site.

I would also like you to know that his product is also available outside the USA. We have shipped units to Australia, South Africa, and Sweden, just to name a few. International shipping via USPS is not all that expensive either.

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Gerard

http://gerardsgarage.com/

Jeff, I hope you've read in other similar posts, my admonition to make sure the external portion of the piston is absolutely pristine. If not, your MC is still going to leak. Guess where the fluid leaks? Right down onto the pedal and your feet, making it easy for your foot to slip off the pedal, so it's a safety issue.

You can polish out minor scratches with some crocus cloth, but any deep scratches or gouges will damage the front seal and allow fluid to escape. Before reassembly, I put that piston in a drill press and polish it while it's spinning. Your end result should look like a chrome finish.

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Gerard

http://gerardsgarage.com/





Edited 1 time(s). Last edit at 10/04/2012 03:04PM by pixelsmithusa.

Thank you for sharing Jeff! That is a great write up, and I am sure will help many! I've done a few of these too and sent them off to Seth (amishindy). He has a really nice website and is much friendlier to Spridget content than MGExperience- no offense intended, speaking purely from experience.

Bri

I did that way back in July, and while I've only had my car drivable for a few weeks (the some one backed into me) I can say my brakes work pretty well for now and no leaking. I am anticipating having to replace or have serviced again at some point though.

What year is your Midget Jeff?

I started another topic here thinking your example was from an earlier model than my 79, but maybe yours is a later model as well?

1971 not sure if its different then later models .

'68 and later are all the same as far as the brake MC. There are a couple variations in the clutch MC.

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Gerard

http://gerardsgarage.com/

Thanks for straightening that out Gerard!

I guess I'm so used to the 1500's being "different" than the earlier models I assumed this was the case here. Now I know different!

Hey Jeff,

I got my MC rebuild kit from Mr. Kirk yesterday!

I'm thinking I might try to tackle this project today. Any chance you have more of your write up to share?

Starting to wonder if I should have paid someone to do this

Bri

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"And then I remembered what they said about old British Engines, if there ain't no oil under 'em, there ain't no oil in 'em." Tow Mater