I went out to car to work on my heater vacuum control plumbing and,...SUPRISE!


My Brake master cylinder is leaking between the cylinder and booster. I suspect the old seals didn't much like my lockup test I did yesterday. Oh well put that on the top of the list now and move heat control down a notch.


I went on-line looking for options and I am a little bewildered as to what I'm finding. The prices are all over the map and all High! I am considering a seal kit but those prices also seem to range from $10 - $70, I talked to Gary at Jag bits and he's telling me the other sellers will send me the wrong parts.


What do you all think? Best place for this part or seals?

 

We've had good success with Jag Bits, but when Nix's MC bit the dust I ordered a new unit rather than fool with a kit (got it from Amazon: Beck Arnley-072-8272).

Reason being, after Years of sitting unused (or even used for that matter) without regular changes of fluid, moisture condenses, settles to the bottom of master cylinders, wheel cylinders and calipers, and pits them.

Honing the pits out of an MC bore was a very Boring prospect for me (always the chance of going oversize in efforts to get ALL the pits out), so I took that short cut.

Orthodox wisdom is to replace both MC and booster at the same time; booster replacement requires lifting the pedal box but that's not hard - tedious but not hard.
(';')

 

Elinor, agree completely, I never hone any brake part.

However if the bores and cylinders are unmarked then you can fit new seals. Best to buy from a good jaguar supplier like David Manners than cheaply elsewhere.

 

I cant argue the wisdom of buying new cylinder. I've rebuilt maybe a half dozen, but they usually only last a few years before failing again. maybe just poor workmanship on my part. I think the booster is pretty tired too cause I have to keep a decent amount of foot pressure on pedal at stops. I seem to remember reading somewhere of people rebuilding those too, but that was in relation to my Triumph.


However I just dropped a decent amount of money buying this car and I'd like to spread out the pain (money outlay) a little. I may try a re-hone and seals just to get it going again then after a bit replace if it doesn't hold.

 

Yes, Greg, I speak that Fluently!

At least I got to drive Nix for a year before the brakes died (that was Exciting!) and had to be rebuilt, including replacing all 4 calipers, park brake, MC/booster, and a bunch of other stuff "while we were at it."

What kept us going through all the disappointments and frustration was the thought of what the car would be when "finished" (They're Never Finished!), and the little victories along the way.

Finally, 3 years later (driving between projects) it's the car we thought husband bought for me at the time and it's turned out to be a Great Car!

But what an Adventure along the way!!
(';')

 

You can use a new S3 (very cheap and easy available) or even S2 MC... if S3 you will need to adapt Metric brake fittings to your older system. If you buy one with the plastic plugs in the MC, you can retain your old remoter reservoir.They are very cheap compared to trying to find a S1 and getting them is much easier... be sure to change the three brake hoses (2) front and one rear one before bleeding.. they will be shot if not recently replaced.

I too have had little luck honing and rebuilding MC.. easier to just buy new ones...

With these old Jaguars... finding something new to fix is the norm... but they are easily fixed compared to modern cars...

 

Agree, New or pro rebuild of brake things vs DIY fixes are by far a better choice. Just too much at stake. SAFETY!!!!


1. My first cars had little if any brakes, mostly lousy if present at all. In the late 40's and early 50's, a far different era than today....


2. Circa 47, or so, I worked at a full service station. Full brake service included. Our boss did most. But, even he was learning. Indeed, wheel and master cylinders were honed and "kits" installed. Pistons, springs and rubber seals. Most came out just fine. But, on occasion, leaks remained. A Wagner instructor enlightened us. Hone out too may pits and the bore is outsized. The seals will fail. If any doubt after a light hone, toss it and replace.


3. Later in car life, I did some hone and seals. I stuck to that advice. And, indeed, circa 75, a wheel cylinder on dear departed wife's 71 Hornet, AKA AMC Rambler refused to seal after a hone.


4. When I built my "Hot Rod of the Forties" project, I availed myself of repo wheel and master cylinders to do the "juice brake" feature.


5. Circa 1959, I bought an engineless derelict 40 Ford pickup. Brakes squirted fluid all over the place. No wonder it had roughly fixed right fenders and a bent front axle!!!
But, the hone and seal was in the "budget". Luckily, it worked. An engine and transmission built from junk yard discards and it ran really nice.


So, squeeze in some things, but not in brakes!!! Just my thinking. accept or decline...


Carl
s

 

Greg:

I also went through the MC replace, vs. rebuild process.

When I got the new MC it was missing the seals between the reservoir and the cylinder. The supplier I bought it from said that is a common problem. So if you decide on a new one, you may want to save your old seals just in case.

I wonder if others have faced the same issue.

 

I Pulled the MC and Its not pretty. Also I'm not sure where to buy Chocolate brown brake fluid?


I found a series 1 MC for $349 not unreasonable. and a booster for $181. I haven't priced an S2 or S3 yet.


Roger, you say the S2 is direct bolt on?

 

I used the S3 MC and it's top mounted reservoir for ease of buying future parts... I have never changed a Jaguar brake booster yet so I have no advice of what fits...

But, as the other post said, the MC and reservoir and the top cap will fit - mine hit the hood brace barely and I cut off a small piece with my Dremel. If it hits the hood, it will tilt the top mounted reservoir and leak brake fluid all over the fenderwell...been there done that!!!

BUT, unless the MC with the reservoir says it comes with the needed seal between the two parts - you will have to order a Repair Kit for a MC to get the two needed rubber seals.. Jag never sold them separately so the the suppliers do the same stupid thing.

Using a S3 MC you will have to get an adapter or reflare one line to match the metric fitting on the MC.... I did one car one way and the other by cutting off and obtaining a new flare fitting and doing the proper type flare.. either way works. You can barely see the silver adapter just to the left and right of the hood brace.. that is where I adapted the metric lines from a S3 from the junk yard.

Black brake fluid is normal since it goes bad over time... since you have to totally bleed all four wheels that is why I suggested this would be the time to get three (3) new rubber hoses... they expand over time and you will have a soft pedal and erratic pulling of the brakes... ask me how I know! Rear only has one line...

Do it once correctly, then you only have to worry about needing rear calipers due to leaks, rear brake pads and E brake pads, when that happens be prepared to drop the IRS....