Series 1 xj6 brake booster
 

Hello everyone,

I introduced myself a few months ago as a 97 xjr owner,

Prior to that I've had a 85 S3 and a 72 S1 XJ6

I wanted to sit in England again so I've got another 72 XJ6.
higher
I need some assistance with the brake booster, no obvious signs of leaking, but the brake application is harder than what I remember for an S1 and the pedal seems to need more pressure when I'm stopped at a light (car seems to want to creep forward) or a stop sign. Not losing any fluid

Are boosters from an S2 comparable with the S1 master? I can't seem to find any boosters for sale prior to 1975.

Would like to sort this out sooner than later for obvious reasons so any advice or suggestions would be welcome.


Cheers

cds

No idea on comparability, but I'd start with checking for leaks, find the hose that supplies vacuum to the booster and suck on it, does it hold pressure? Next step is to suck while someone applies the brakes. Should hold a vacuum, if so then look elsewhere for problems. Let us know what you find.

Series 1 booster has a different bolt pattern for the attachment on the vehicle side. They look the same as series 2/3 but they are slightly off.

You may be able to fit a series 2/3 booster but you will have to change the pedal box too.

Google search turned up several
 

Here is one link:

72 1972 Jaguar XJ6 Brake Booster - Brake - Centric - PartsGeek

Thanks icsamerica NathanDD6 and Roger Mabry,

Vacuum hose system has no perceptible leaks, Im not losing any brake fluid,

I do get some leakage with the one way valve at the top of the booster, I'm going to try to seal it temporarily with RTV to see if it helps.


cheers


cds

It won't help, been there done that. You have a failed booster, the only cure for which is replacement unless you have equipment to repair the diaphragm.

You might as well get a new master cylinder while you're at it and never have to touch either of them for years.
(';')

Might go that route indeed.

I think you can get your booster rebuilt. I used to have a '67 Cougar that I had the booster rebuilt. I can't remember who it was. I boxed it up and shipped it to them.

I'm sure you could find someone on the interweb

I had my S1 booster rebuilt. Sorry can't remember the shop but I believe it was near Los Angeles. I boxed it up an sent it in the mail. It came back with a yellow zinc plating. Try searching inter web.

A bit fuzzy here, but t might help a bit.


1. I seem to recall that the plastic bit that fits into a grommet at the booster is not a one way valve at all, merely a fitting. Elinor might be referring to seeking to stop a leak there with RTV.


It seems that a one way valve would be needed. perhaps it is on the manifold or on the line near there.


Pause:


I went out to the garage and checked my 83! Confirmed. Red plastic spigot at the bellows. Metalic one way valve about two inches away in the line to the intake. Different car, yes. Concept the same.


2. Nathan's idea on checking the system for a leak is sound. If you want to finesse that, HF sells a slick "MItty Valve/pump. Guage included. Pump the booster down, close, observe the guage. will it hold a vacuum or does air seep in and the numbers go down.


Also, adaptable to brake bleeding that is more sophisticated than the squirt on the floor method.


I've a dim recollection of a bellows rebuild service in the Nw USa???


CArl

Hello all,

I believe it is a one way valve, it's been awhile since I had an s3 so I can't remember if it was external.


I can't seem to find a diaphragm in any of the rebuild kits so I'm going to go with Either suggestions of new/rebuilt servo and possibly going through the master cylinder as well.

The car is rather new to me.

I just dread bleeding the rear brakes.....

I'll post once I've sorted it out,


Regards


cds.

Bleeding rear brakes is easy
 

Changing the parts is not as easy but the bleeder screws are accessible... I would change out all the rubber brakes hoses at this time (3)... that way you can put in all need fluid and bleed all four brakes.

A Mitty Vac sourced from HF might assist in the bleed process.


If new hoses planned, a good idea, even if mission creep, why not
new bleed screws?


Way back, a decade or more, I was having trouble bleeding the cylinders of our 71 AMC Hornet. Actually a Rambler!! Nice car, bought at a bargain and with a story !!!


Dear departed wife's assigned car. So, her assignment was "pump
and hold"! Wasn't working??? Fired up the 258 CI six to get boost.
All right, got clean squirts, sans bubbles. Old tech, squirt on the floor. Success. Wife thought I was a genius.


Carl

JagCad,

I do have a mityvac, I used it to check for leaks in the vacuum lines, however I prefer to use my brother, we have a good routine after all these years.

Roger
I remember rebuilding the rear calipers of my previous 72 XJ6 bleeding wasn't impossible, maybe I'm thinking of bleeding a friends xke's rear brakes?

Anyhow, the hose suggestion have me thinking that maybe the pedal creep is due to swelling brake hoses?

LnrB

I rebuilt the earlier girling boosters in cortina's and
those in the later girling lockheed incarnations in élans and europas. Id do it again but either my googling is sub par (as Roger can attest to) and I can't seem to find a diaphragm for it. Aside, its my daily driver, so I don't want to be down for too long if I can help it. So thinking new for now.


regards


cds

(I'm using my initials as I am also a Carl and wish to avoid confusion)

CDS, A good name!!! For a good reason or a no mater reason, my boss after my return to civilian life after army service in 55 was a Carl. Did he feel a kinsmanship and offer me a job? Did I feel the same and accept ? I kinda think so. A fork in the road of my
career. It went well....


Why did my Dad's English/Irish/scotch parents choose a then unpopular German
name? We never knew....


Oh, my dear departed wifey was German born and raised. She had a cousin, Karl !
Cousin, his spouse and I got along well, not long after WWII in circa 53.


Names????


Carl
Carl