Any advice welcome,
Have started to repair the braking system on my v8 250,
The rear calipers are off and it looks like the cylinders are seized.
What is the favourite remedy repair or replace?
Who in the UK have people used to do this?
Cheers Steve.
Have done both replacing some cylinders and cleaning them up with new seals. Depends how rusty they are inside. light corrosion will come out with fine wet and dry paper. I’d see if you can pump the piston out without the pads in. Try not to let one come out fully so the other will come out too. If off the car then compressed air might work if not too seized. Watch it doesn’t shoot out and injure you though.
You can clamp the piston in a vice and work it back and forth and use a couple of screwdivers to lever the cylinder up from the piston.
Once the piston is out you can see how bad they are.
When i last replaced some i had to return the old ones so avoid damaging it if you’re thinking of doing that.
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I’ve done both. I used past parts for the refurbish route and purchased the anodised alloy ones when I went the replacement route
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Thanks for that,
What was the cost of the refurbed ones from past parts?
Use caution in removing pistons - compressed air can turn the piston into a projectile. I recently removed some completely seized Mk10 pistons by welding a grease fitting to a brake pipe nut and pumping them out. Safe and always works. Unless the bore is really good, I’d routinely sleeve them, and then you don’t have to worry about it again. I use Apple Hydraulics (no affiliation). They have reasonable prices, a quick turnaround with parts off the shelf, or sleeving of your own if you wish. I’m sure there must be a counterpart in the UK.
I can’t remember but I think these days it makes more sense to go with the new units and get the benefits of the revised seals.
With best regards
Philip Dobson
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Can you expound? I wasn’t aware that the new replacement units had different seals.
I too usually have my cylinders (or pistons) sleeved in SS
I use the cars hydraulic system to free stuck pistons by splitting them, and blocking the hole with the bleeder.
Often, you have to tap the piston back into the bore to break the seizure using a brass drift,
connect up the half caliper to the brake hose it came from, do one at a time, preferably do not use power assist and/or push the brake pedal down all the way
I restrain the piston with a g-clamp
imo, you should avoid lever upon the piston/seal lip, as they break easily
Depending on which type you go for some of the newer (the alloy ones) use a more modern seal in the bore with sliding piston
With best regards
Philip Dobson
I found a used set of SoCal stainless housings / pistons on ebay, anyone ever used them? any idea if they used std. seals? I have a few old / rusty units here that may be better than yours, may well not be though! having said that I had no real trouble re-sealing my servo and both master cylinders after standing for 40+ years,
Thanks for the views, I’ve now bitten the bullet and bought 4 new cylinders.