Thread: Wild price differences on clutch master

Don't know but a fella at the LROC had to replace the one on his 130 and bought one from Repco which is performing admirably.

gees mate you could wear out 3 of the karcraft units and still be ahead.

glen

This clutch master cylinder is the same as the one commonly used on trailers with override hydraulic brakes, and also fits Series 2/3 with a separate reservoir (usually with power brakes), so it is commonly available outside the "Landrover" supply chain, and probably a lot cheaper. Quality presumably does vary, but I know of nothing to suggest that price is an indicator of quality. Some, mostly those with late model Defenders, seem to have to replace them very frequently, but I don't know why.

John

I think it is because of poorly adjusted clutch pedal stroke heights. Mine was done under warranty and had to be right to the floor to disengage and re engaged just off the floor. It is quoted as needing to have the pedal set to 140mm off the floor fully disengaged. Mine is now around that as I reset it. So I presume this fully strokes the cylinder and does not cause a wear spot in the cylinder allowing it to bypass and eventually leak.

Clutch pedal setting
1. Loosen both locknuts on master cylinder push rod.
2. Check distance from lower edge of clutch pedal to floor. Correct measurement is 140 mm (5.50in) without floor mat.
3. Adjust pedal stop to obtain correct setting.
4. Adjust master cylinder push rod to obtain approximately 1.5 mm (0.06 in) free play between push rod and master cylinder piston.
5. Tighten push rod locknuts.
6. Check operation of clutch pedal and ensure that there is minimum of 6 mm (0.25in) of free play before pressure is felt.


Trev.

my defender one has just started to leak so i might go the trailer part as a option ill wait to hear the pros and cons

mines been replaced a few times as well......
im just thinking.....maybe its not the master cylinder but rather the brake fluid....?

there are some cars out there.....toyota and nissan especially.....where the cap
on the brake fluid reservior states to use only dot3 brake fluid.....
todays brake fluid (dot4) exceeds dot3 specifications.....so is used in its place.....
after all it is a better brake fluid...is it not...?
this somehow manages to ruin the seals in the master cylinder way before their time.....
using the lesser grade dot3 fluid does not cause any problems......







now im just wondering if we may be experiencing a similar problem with our landys......



im open to any feedback....and also very curious as to why they are dying so early.....

Zook, this was postulated on by some Seth Efricans who arrived at your conclusion on the old LRE board some years ago. They claimed they didn't have any more probs when sticking to DOT 3 fluids. I thought it was a load of cobblers, but you never know.......
FWIW, I've been through one cylinder about 40,000km ago, current odo is 189,000km. Didn't bother putting a kit through it, just swapped the m/c. Didn't use my usual brake fluid that time (Castrol Super Response) just threw in some cheapy Fuchs brake fluid, can't remember the spec was but it's a very pretty blue.

Funny thing is that the Girling master cylinders were always the ones used in race cars as they were reckoned to be the most reliable !
The highest boiling point DOT 4 fluids and exotic stuff like Castrol SRF was always used there, so

Interesting thread this has turned into. When you think about it, the fluid demands in a clutch system are a lot less than in a brake system - no heat problem. But on the other hand it gets used more than the brakes - four or five times every time you go from stop to top, at least once when stopping, compared to the brake once when stopping, so wear on the seals and cylinder are probably more of a concern. This probably depends mainly on the access of dust to the system and the lubrication ability of the fluid.
But I suspect often the problem is not wear, but corrosion of the bore due to the fluid absorbing water - and here the lack of heat may be a detriment, and the fluid becomes critical. And, of course, there is the question of compatibility of the fluid and the seal material. Which should be OK for any reputable fluid or seal/cylinder.
John