I have a 1973 E-Type Series 3 and recently have issues with brakes master cylinder leaking fluid.
There is a lot of conflicting information out there on the Dot 3/4 versus silicone etc. I replaced the master cylinder with new aftermarket part and used Dot 4 but the seals leaked again after a week so not sure which way to go? Anybody else have issues like this and more important a solution!! Thanks in advance!!
Morning Kevin,
I suspect that it has to do with crappy seals rather than the brake fluid, besides that, the folks at White Post will not warranty their rebuilds if you use DOT 5 (silicone). Since you used DOT 4 that’s a non issue. Hate to say it but it’s time to call your supplier and get a replacement or send your original off to someone like White post or Apple Hydraulics for a rebuild.
Cheers,
LLynn
This is a reply to Kevin who has leaky seals after replacing the master cylinder. I not too sure i understand this !? If you replaced the master and it leaked then the master is faulty from the start. Maybe you could share a little more info as to what leaked where! I assume that no Silicone fluid was put in the system.
I agree, a leak in the first week suggests a faulty part.
Now if Kevin had used DOT5 then some would cite this as proof that DOT5 is bad stuff.
Sometimes parts are faulty and sometimes parts fail w/o regard to what fluid is in the system.
I noticed a fluid leak under the car and the master brake fluid reservoir empty and the the slave cylinder over full. The masterservo unit was full of brake fluid and small traces of white smoke form exhaust on start up. The master cylinder and servo were replaced with new aftermarket units. New Dot 4 fluid replaced and brakes bled. Car ran fine for a week on just short runs. I left the car for a week and noticed the fluid leak is back and master fluid reservoir now almost empty again.
Hi kevin, Thanks for the new information. Transfer of bf from the fluid resevoir to the servo is usually caused by a fault in the Master cylinder…probably a leak of bf past the piston seals.This could be caused by a seal being fitted back to front, or if this is a refurbished master, it had pitted walls in the cylinder. Fluid then loads up the servo, and some fluid gets into the vac lines and then into the intake manifold a then gets burned in the engine…hence the white smoke from burned bf! was the master cylinder really new ? Not that it matters, but I’m not sure about "masterservo " ???
John,
A few minor corrections:
Transfer of bf from the fluid resevoir to the servo can only be caused by a fault in the Master cylinder…It can only be due to a leak of bf past the piston seals.
The new master cylinder was defective from day one. There is no other possible explanation.
Regards,
Ray L.
1 Like
Thanks John for the correction- you are right of course it’s the Master Cylinder with Servo attached. I was led to believe these aftermarket units were new but reading previous buyers they seem to be refurbished units.?? Although they look all shiny and new. The emptying of the master bf reservoir into the slave appears to be a Siphonic action (please correct if wrong). When the suppliers buy these from 3rd parties who actually bench tests them to pressure to ensure moth conformity and reliability??? It’s a bit worrying thIs could have failed when I was out cruising in the hills or motorway!! So my solution is to return to the supplier with unit and no other recourse form them.
Kevin, So you need to get hold of the vendor pdq and get a master that works.I should add ( and LLyn has already mentioned this ) resleeved masters can work very well.I have had 2 resleeves followed by my own rebuilds, and the systems work well.Good Luck
UPDATE.
The parts supplier was notified and it seems all his stock was faulty from his supplier!!
To that end a new one was provided after bench testing and is being fitted tomorrow.
Watch this space and will update on results.
Thanks!
I just ordered from Welsh what I hope is new servo unit !
Patrick
'66fhc
its going to be a Girling or Lockhead but check it out before you fit it !!
Might be a refurbished after market part!!
Kevin. How do I ck it out ?
I know the units from Welsh in the past were new. Description of parts now listed are described as “newly manufactured” not remanufactured?
Glenn
70E
I spoke with Welsh saleswoman and she noted that they have not had any complaints regarding the current stock of Etype servos, but in 2012 there were problems.
Patrick
'66 FHC
Scary thing is that I cannot find what the issue actually is!!! Is it the new DOT4 brake fluid, poor quality control from suppliers, poor seals, incompetent component builders, etc. etc. My solution would be to have each and every component tested and issued with Certificate of Conformity (Test Data Sheet). Mine is being fitted today (third time) so will test over weekend.
By test, do you mean work the brake pedal operation and look for leaks? Curious if you have to hook vac booster hoses up to do the test ? Someone mentioned the booster vac could pull the brake fluid past the piston seals ? I’m tempted to leave the booster out.
Patrick
'66 fhc
I have heard of problems with the “new” master cylinders leaking,
they are very cheap, and must have been made in China, or similar, there may be some tolerance issue, or poor quality metal, and who knows what quality of seals are used.
I prefer to opt for the lifetime solution of SS sleeving, it was not much more than an el-cheapo new one
believe the “major” vendors sell MC also, but much more expensive than a sleeve job
Well here we are on Monday evening no word or contact from the part supplier nor the garage!! It’s so frustrating when these parts are expensive and really should have better quality control being a safety critical system for the car! People say No News Is Good News! In this case I am about to jump up and bite my own a**…",",
The master cylinder is fixed to the pedal box. Assuming you aren’t talking about that one, I believe the Lockheed master and servo assemblies are usually new, which is why they don’t generally credit for a worn core in part exchange.