Help needed on E-Tpe master cylinder rebuild

[billca]

I'm rebuilding the brake master cylinder on my 67 E-Type and need some suggestions for removing the piston assembly.
I have removed the spirolox circlip and the circlip as shown in the manual Fig. 16, Supplementary Page L.18. The piston moves smoothly in the bore and bearing. At this stage, the manual says "The piston assembly, complete with nylon bearings and rubber seals, can be withdrawn from the cylinder bore." The piston assembly does not come out easily; in fact, I cannot get it to budge with the normal pulling or application of air pressure applied at the outlet adapter. I have not applied heat and I have not applied air pressure to the inlet. I also have not checked to see if the nylon bearings can be purchased in case I destroy them on removal. Any suggestions?
Billca

 

[Webserve]

Billca,
I suggest you find an independant Jag mechanic with a bit of experience with these brakes. I don't mean this in any negative way, but the Series I 3.8 litre XKE used a front and a rear pair of Girling Master cylinders same as the Mark X 4.2 litre whereas the 4.2/V-12 Series 1, Series 2 and Series 3 used a Lockheed/Dunlop system -- the same as on my 420. The Master on my 420 literally fell apart when I removed the circlip and slid the piston out of the housing. The only thing that could have possible held the piston assembly in was the rubber seals sticking to the sides from non-use. In my case, air pressure used in the hole that the reaction valve connects would certainly have forced the piston out. There was nothing to block it.

Webserve

 

[franks]

Hi: Use Hygraulics-- somehow pressurize fluid such brake fluid, water, or oil or grease to force out the internals. How about: Connecting grease gun to an piece of old brake line , plug the other MC opening, attach to Master C and pump. The pressure should force the plunger and seals out. The internals should come out in slow steady progession. If you use oil or grease you will need to throughly clean the MC of oil/ grease before you rebuild the MC. The oil will make seals swell if MC is not cleaned of oil.

Or: You can carefully heat the MC all around with heat gun, blank off one opening and use compressed air to push out the MC internals. See if you can inject brake fluid into the MC to lub the seals before you start heating.You will need a rebuild kit of new seals, because of the heating. Be ready to catch the plunger, it will shoot out when it gets loose. You may have to repeat this process before you get the plunger and seals out. Good luck

 

[billca]

Re: Help needed on E-Type master cylinder rebuild

Webserve amd Franks,
Thanks for the suggestions. I'll try them this coming weekend and see what happens. If someone else has a suggestion, I'm open to everything at this point. I'll let you know what works.

billca

 

[John S Farrington]

Re: Help needed on E-Type master cylinder rebuild

What you are attempting to do is a very complex job. You will put a significant time in R&R. In order to rebuild the E type masters and servos and not become an expert on removing and installing the units through multiple trials, I recommend that you give the rebuild job to a source that does it routinely and has the expertise. The reconditioning of the brake units (since it also a safety matter) should not be attempted without experience. It is a very complex job.

 

[franks]

Re: Help needed on E-Type master cylinder rebuild

John: I do agree with you, that the brakes are very serious matter and should not be compromised in any way, but from first hand experience the job of rebuilding the Jag MC is straight foward in replacement of the seals. The manual has great pics and instructions.The hardess task is usually getting the plunger and seals out of the old MC. Once out, the surface of internal cylinder bore needs to be evaluated for corrosion and if present the need to reslieve or not. If the MC needs reslieving then the job must be done by a pro, like White Post co. In my opinion the cost and time to you in having someone take care of the MC rebuild is I think worth it. And look, you would have gained that experience and knowledge if you need to do it again. In things about my car, I'm a firm believer, if you want the job done right do it yourself, if you can.

 

[John S Farrington]

Re: Help needed on E-Type master cylinder rebuild

I have had excellent results and could not ask for more improvement than recycling the E type MC and servo through Apple Hydraulics. White Post is another good service but a little more expensive. I do recommend that while you have the E type master out, also refurbish the slave servo. It will be a lot easier than making two R$Rs down stream. I have the philosophy to do my own work but use rebuild services for component turn around if available and convenient. I guess this practice has come from dealing with some of the later model Jag components. Coventry West does very good work and at fair prices for things like differentials and steering racks.