Brake master cylinder.
- Thread starter phil
- Start date
Fluid runs down the pushrod when they leak, so feeling there will let you know.
Provided the master cylinder has been resleeved, then typically the seals are all that need replacing. Sometimes the nylon castle for want of a better word that resides on the end of the piston assembly is badly degraded and will need replacing.
If another NOS master cylinder had been fitted previously rather than having the original resleeved then it will almost certainly require resleeving. The bore must be perfect, free of any corrosion etc.
It would be advantageous to replace all the brake fluid at the same time, cleaning the gauze trap in the base of the fluid reservoir while the opportunity presents. Using a silicon brake fluid is not advised, rather a polyethylene glycol based fluid is preferable.
Ron.
Provided the master cylinder has been resleeved, then typically the seals are all that need replacing. Sometimes the nylon castle for want of a better word that resides on the end of the piston assembly is badly degraded and will need replacing.
If another NOS master cylinder had been fitted previously rather than having the original resleeved then it will almost certainly require resleeving. The bore must be perfect, free of any corrosion etc.
It would be advantageous to replace all the brake fluid at the same time, cleaning the gauze trap in the base of the fluid reservoir while the opportunity presents. Using a silicon brake fluid is not advised, rather a polyethylene glycol based fluid is preferable.
Ron.
The Rovering Member
Well-Known Member
Well, honing a slightly pitted bore can work wonders. I did that to Bruiser's master & it's been as good as gold for two years. You make your own choice depending on the bore condition.
On the point of re-sleeving, we had our old A30's master done with S/S, but the braking was never right afterwards. I took it off for the third or so time to re-rubber & took it to our local factor. One of the guys commented that it was a lovely mirror finish but he didn't think it should be that way, so he rung Lockheed & they said that mirror was the worst possible finish, as the rubbers wouldn't be able to seal against it & to hone it out, which they did for me. It was perfect afterwards.
On the point of re-sleeving, we had our old A30's master done with S/S, but the braking was never right afterwards. I took it off for the third or so time to re-rubber & took it to our local factor. One of the guys commented that it was a lovely mirror finish but he didn't think it should be that way, so he rung Lockheed & they said that mirror was the worst possible finish, as the rubbers wouldn't be able to seal against it & to hone it out, which they did for me. It was perfect afterwards.
Once properly rebuilt, the booster (servo in the U.K and likely in other countries,..but in Australia we call them boosters) should last for 10 or more years without giving any problems. They will let you know when the time is getting close as the brake fluid level in the reservoir will slowly drop and is leaks into the vacuum chamber. Another symptom is a brake pedal which pushes back at you when you are trying to pull up, most disconcerting let me tell you.. :shock:
If they have not been rebuilt correctly, then a wooden pedal is likely as are brakes that on light applications stick on or lock on depending... :evil:
Ron.
If they have not been rebuilt correctly, then a wooden pedal is likely as are brakes that on light applications stick on or lock on depending... :evil:
Ron.
phil wrote,...
Why do you want a new master cylinder? What did you do or what is wrong with the current one?
Ron.
Why do you want a new master cylinder? What did you do or what is wrong with the current one?
Ron.
So how did you get on with your master cylinder Phil? What happened to the one in your car?
Ron.
Ron.
Hi, only just saw this. I managed to get a master cylinder from wins.
I stupidly ordered a servo the day after before the master cylinder arrived as I then convinced myself that was the problem. Basically my brake pedal started sinking slowly and it progressively got worse. Replacing the master cylinder cured. Irritatingly though, I now have £250 worth of servo here all because of my impatience.
I stupidly ordered a servo the day after before the master cylinder arrived as I then convinced myself that was the problem. Basically my brake pedal started sinking slowly and it progressively got worse. Replacing the master cylinder cured. Irritatingly though, I now have £250 worth of servo here all because of my impatience.