I removed the Master Cylinder (MC), Servo and Brake Pedal Unit to remove some corrosion. That job is all complete so everything was refitted. All was going well and I even made sure I had the correct EPDM rubber hose to connect the Reservoir to the MC.

Today I tried to bleed the system, but that's when it all went wrong. The MC just didn't feel right and I could hardly get any fluid to pass through the Calipers?

I did a search and found this thread:

https://www.jaguarforums.com/forum/x...ng-else-84070/

I fear that I may have succumbed to the effects that icsamerica speaks of, namely that an old MC will have had limited travel during its long service life, but when a bleed is conducted the MC sees its full travel and the difference in wear between these areas can play havoc with the seals.

So, the question I have are:

1. If I'm going to change the MC is it worth upgrading to an S3 item?
2. Does the S3 item bolt straight up to the S1 Servo?
3. The pictures I have seen look like the S3 MC has its inlet ports on the other side compared to the S1, so I'm assuming I will need to make up new brake lines for the first short run? EDIT: I've seen that these are LHD or RHD fitment and therefore new pipes would only be needed for a LHD fitment MC.

Your assistance is greatly appreciated.

 

Yes, you will need to cut off the old ones and flare new fittings onto the existing ends... I just did this to a '72 XJ. It all can be done with the
lines still connected in the car... do it at the fender well.

You will need to use either the current remote reservoir or convert to the S3 type. If converting, you will need the pins and clips that hold on the reservoir and a rebuild kit for a S3 MC... why? Because Jaguar put the two needed rubber seals for the reservoir into the rebuild kit... crazy idea.

Plus, you will need the new S3 cap for the reservoir and the rubber cover... the lines can be lengthened and it will work perfectly. There is also an inner
"filter piece" that should be obtained. Buying a used MC complete from a wrecker is the easiest way to get all the needed parts but make sure it is still full of fluid (the plastic cracks). The used MC can be then used as a core if buying a rebuilt unit. You could remove the brake lines from the S3 and adapt them to the S1 (I did this on my '71 car the first time).

Obtaining a rebuilt S1 MC is very expensive in the USA, cheaper to convert to a S3 MC by far... once the lines are adapted, the next MC event will be easy.

Then flush and bleed the system completely, starting at RR... good time to make sure the three (3) rubber brake hoses are newish or change them now.

 

Good detailed stuff.


the only thing I might add is that bleeding the Mc on the bench prior to the install can often preclude bleed issues on the car. I've found that the car must still be bled, but much easier. On one reluctant car, I used the engine idling to get more boost. Coincidental, I am not sure. Perhaps, my helper, dear departed wife, just didn't stomp hard enough sans boost.


Carl

 

I did that step but forgot to tell about it... just hold it in a vise - fill MC with fluid and push from the rear of the MC... air will be purged.

Try to install it with the fluid in the MC - put the plastic plugs back in that come with the MC.. easy to do after figuring out how to hold it while putting onto the booster. Tighten into place and then install the brake lines.

Be sure to cover the area under the MC with plastic or you will be repainting that area.. brake fluid works as a great paint remover.

 

Thanks for the replies gents. I've actually got an MC repair kit, but it's just a few seals. If any of the metal parts are worn, it probably won't help.

I've got a decent brake pipe flaring tool and some M10 and M12 male fittings. It would appear that finding a new MC is going to be the hardest part if I do decide to go with the S3 MC.

I might pull the old MC off again and see what the actual damage is?

 

We bought a new master cylinder for my S2 in March 2014. Husband found one at Amazon of all places, but it's Beck-Arnley. I think he simply Googled the part # (072-8272) and found the listing.

He paid $181 US + $14 shipping.
(';')

 

I saved the old MC, you can have it if you need some of the internal parts... not sure how good they are? I usually buy new brake parts, have never had any luck rebuilding things that have pistons etc...

Shipping is not just a little amount from So Cal, Zip is 91741-2731.

But, finding a new S2/S3 MC's is FAR easier and cheaper than Series 1. You could keep your remote reservoir (the new one came with plastic plugs that you leave in if using the remote reservoir) and save a lot of work and some money for the initial used reservoir parts, pin/clips etc.

 

Roger, that is a very generous offer, but I have just paid for a reconditioned S1 MC from a company in Melbourne, Australia called 'Jagdaim'. You are a credit to this forum.

Jagdaim said they no longer stock new MC for any Series XJ as they're just too expensive!

It has cost just under A$250 on an exchange basis, which I can live with. They basically strip them down clean up the bore and sleeve them.

Hopefully it will be with me (in Sydney) tomorrow so I can get it fitted and bled over the weekend.

Thanks again Roger.

 

The reconditioned MC arrived yesterday and I fitted it today. I was very cautious not to let the MC travel too far, and I'm not completely happy that the brakes are as good as they could be, but they are working.

The car hasn't moved for over a year and so the Discs/Rotors have some corrosion that needs to be worn off too. Main thing is that they're working!

 

If it's been reconditioned, it *Should* be the same diameter through its full depth.

We bled my whole system just last week, and even after running a full pint of clear fluid through the system, I still had spongy pedal.

So we let it sit a few days to allow any small bubbles in the system to merge and husband went around yet again. He got more air out of not one but TWO calipers! After that I have Rock Hard pedal.
(';')