to removing the internals of the brake master cylinder? I've removed the snap ring but cannot get the piston and bearing/seal carrier to come out (10878 in the diagram). I've tried gripping the piston in soft jaws and yanking on the cylinder body to no avail. I don't see any other impediment to removal when I study the exploded views and cross-section in the shop manual.
The light blue bearing has two holes in it, and I can rotate it (although not easily) but it won't budge axially. I've searched in vain for some non-obvious pin I need to remove.
Suggestions?

Ken

 

Hello Ken ... from Ken ... and with greetings from down under;

I too, am ready to give up ... nothing I do allows me to zoom on your attached thumbnails. So, despite trying to recall the many times I have dismantled these in years long past ... the following is strictly from memory. Like you, my initial focus on those two annular holes had me fabricating ways of "unscrewing it" out of the bore ... in the end, I made up a special tool and invested hours before giving up in disgust.

Firstly, you have removed the internal snap ring from its internal groove. Then, that leaves the blue part you call a bearing ... which is actually the part to the extreme left of your parts diagram (and which I cannot read ... grrr). Theoretically, once freed from the restraint of the snap ring, this should now pop out ... but never does as bore wear and corrosion impedes it. Your efforts to rotate and gain a millimetre or two in fore-and-aft travel do help break the corrosion seal.

Hardly a secret, but cap and seal the spare pressure outlet and use compressed air on a rubber tipped nozzle (good seal) in the other outlet to pop it out. Take care as, once freed up and over the wear "ridge", all the internals will follow ... difficult to work out how to re-assemble if you just cannon-shot them across the workshop (ask me how I know ... but you only do it once). You may find that wiggling that central piston rod will help.

By way of answering the question you have not yet had the chance to ask ... No, don't just renew seals and ignore the cylinder bore and that "wear ridge". Hopefully, there is so little wear and corrosion that a simple hone will smooth and restore everything to pristine condition. (Yeah, and that jolly red man at Xmas really does live at the North Pole). Let's cross that bridge when you get to it.

Hope this helps, and please keep us posted on your progress.
Best wishes,
Ken

 

Well, I got it apart by locking the piston in a set of plastic jaws in my big vise, resting a piece of 4x4 on the flange of the body and giving it a good whack with a 3 lb dead-blow hammer. Worked on the second try.
Oddly enough, parts 10878 and 10882 were installed in reverse order compared with the exploded view in the parts manual. The lip seal was installed in the proper direction to seal. The back of the lip seal had a light coat of RTV on it. Something the factory did in 1974, or has someone been into my master cylinder sometime in the last 40 years? The car only has about 10,000 miles on it.
I'll clean and examine the bores tomorrow, but a quick look suggests that they are OK (fingers crossed).

Ken

 

Wow ... Very surprised it took that much effort to extract. Something really amiss there... and you point to reversed order of parts on dis-assembly, so I would suggest that someone has definitely been there before you. The assembly line simply did not make those sort of mistakes.

Can I also offer the following. Mileage is irrelevant when considering the long term aspects of hydraulic brake systems ... its all about age. With its hygroscopic nature, brake fluid starts to attract moisture the moment it is exposed to air, and this is the basis for its recommended total change of brake fluid every 2 years ... because the master cylinder fluid reservoir cannot be an airtight system. That moisture contamination is the source of rust corrosion inside master and wheel cylinders and steel brake lines ... witness the difficulty you had extracting the piston sleeve ("bearing").

Not many of us present or former owners can look at our 40-50 year old car and say with confidence ...
"Yep, I know it has had 20-25 brake fluid changes ... and that's the date I renewed all the brake lines."

Back about 10 years ago, I had the thrill of driving a Series 1 E-Type with far less miles than yours ... (mine at the time had about 100,000 miles) ... that car had lived permanently in a garage on blocks and had done less than 100 miles in over two decades ... just started and run every month for lubrication. Those brakes were downright dangerous ... I couldn't get back into mine quickly enough.

So Ken, best wishes with your project. Low mileage E-Types are few and far between but still require as much effort (or more) to keep them up to the bar.

Regards,
Ken

 

Hi Kens,
A third Ken chiming in....
I found rust in the barrel has a lot to do with the blue nylon thingy being reluctant. Yes, compressed air together with a SS sleeve insert can be your friend.

 

Fortunately the long small bore where the moving parts are was in quite good shape. I honed it and the area where the blue part is. There was a little rust track where the o-ring seal is, but it cleaned up well. When I reassemble the parts in proper order, the o-ring will be in a new position anyway, so I think I'm good.
I looked at my 30 year old tube of Girling brake grease and decided it would be better to get new stuff. Fortunately and Lotus parts place has a modern replacement.

 

Hi Ken,
I've dismantled many that have been stuck by blanking off the appropriate holes and using a grease gun attached via an adapter. Its similar to using compressed air, but I with more feel and control. It works every time.

Regards,

Bill

 

Hello Bill,

Thanks for a great tip ... also much safer than my method I guess, but I'm now a victim of what I've learned that works.

Bill ... If that's Sydney in the North (ie Canada) then this is yet another really useful tip that has successfully been exported (like our Jaguars) half way around the globe. If, as is perhaps more likely, you hail from Sydney in the South (our capitol of NSW, but south of my home in Coffs Harbour) ... then please jump over to the Australia/NZ section of the forum and shout a big "hello". We need so much of that knowledge; all your tall tales and true; anything and everything Jaguar.

Best wishes,
Ken

 

Hi Ken,
Yes, I'm from Gosford in NSW, just north of Sydney. As you can see, I'm new to this Forum. How does one move over to the Australian/NZ section.

I also use this same grease gun method to remove stuck in brake pistons.

Best regards,

Bill

 

Hi Bill and welcome to the forum.

Scroll to the top of the page,at the top left hover over the "Forums" tab then go to "General Jaguar Forums"tab,from there go to the "Regional" tab. Click on "Regional" then scroll down to "Australia/New Zealand"...or follow the link below.

Australia / New Zealand - Jaguar Forums - Jaguar Enthusiasts Forum

See you there.

 

Ken
If I recall correctly the parts manual shows the seals in reverse (not correct) This subject has come up on another forum. I have not had good results in rebuilding these cylinders, even when having them re-sleeved. I prefer new parts for masters, but the new reaction valves are iffy .

Glenn

 

Hi Glenn,
What problems do you have in the rebuilds? Once apart, and even that is not difficult with stuck units using the grease gun method, the rebuild is quite straight forward.

Regards,

Bill

 

Bill

Problem with the rebuilds I have done or had re-sleeved is that they don't last.
After a few years they leak or seals fail. maybe just my bad luck. My rule for brakes is to just replace with new. Have rebuilt calipers on my series 2 with stainless pistons and new seals and no problems so far. Also did the same on XJ6 and replaced master with new (cheap).

Glenn

 

Hi Glenn,
You must be damaging the seals in some way during assembly. In my opinion, a reconditioned unit that's been sleeved (stainless liner) is actually better than the original manufacture. If you manage to get the seals assembled intact, then there is nothing that will cause leaks, other than natural aging and wear. The stainless liners are less apt to cause wear to the seals than the cast iron. I've never had a problem with the many I've done, and I buy used master cylinders whenever they come available, for the purpose of reconditioning.

Regards,

Bill

 

Hi Bill and Glenn,

Sorry for my dropout ... I must have accidentally unsubscribed and missed your followup posts until now.

Yes, our experience mirrors yours Bill ... although early brass sleeves we had used were good, some were damaged during rebuild and all suffered somewhat from porosity that was little better than the cast iron original. Stainless steel sleeves, on the other hand, were a brilliant improvement on the factory originals. They were an automatic upgrade on the racing Jaguars I worked with, and even became something of a defacto upgrade on many road cars across the 70s thru 90s.

By turn of century, the casting materials and/or processes were radically improved ... and based on the porosity of many earlier examples we saw, it needed to. Based on our 35year affair with our 4.2L Series1, the s/s sleeves fitted in the 70s when we got the car, aided by regular 3yearly complete brake fluid flush and replacement, and workshop record of 3 changes of fixed and flexible lines, kept the brakes rock hard and leak free, right up to the point when it left us earlier this year.

Just my 2c, but offered for free,
Ken