Re-sleeve front brake cylinders?

[Devildog]

Thanks to all of you for great information about brake Avanti components.

I have a front caliper seal that suddenly started leaking. Is the seal kit same as used in say a 63 Jag XKE ? Dunlop ?

TRW has a kit WO-133-1622306. Although the Apple Hydraulic in NY sounds like a good option to rebuild, I might do it just for the heck of it

Thanks all

Joe

[WayneC]

Devidog:

I believe it's the same kit as for a Jaguar E-type 2 1/8" bore (also used on Mark 2 Jags), but I think later XKE has a slightly larger bore (2 1/4"), which may require a different kit (or maybe not, I'm not sure).

I have a notation in my parts book that the front cylinder seal kit is Girling SP2556, about $40 for a 4-cylinder kit.

Probably any Avanti parts dealer can sell you the seal kits.

And just to muddy the water, here's an online vendor offering NOS front cylinders for $100 each

https://www.studebakerparts.com/studebakerparts/store/s/agora.cgi?product=brk4&cart_id=4704.31055

(Apple price to resleeve your old cylinder in brass and add new seals is $95, which arguably may be the better option in the long run)...

[warren55]

I've ordered several parts from the above vendor and I've been very happy with his service, especially shipping since he uses Priority Mail which is usually much quicker and cheaper than UPS. I'd contact him about them if you're considering that option.

[Devildog]

Wayne and Warren, thanks for comments and contacts.

This brake fluid leak has got me stumped. It occurred suddenly (not progressively worse). I loose all the fluid in front resevour after about 50 miles of stop and go general driving.

I assumed a piston/cylinder seal; however, I see no indication of leak at piston in the calipers (I pulled the wheels so I could inspect). I had a helper pump the brakes and observed all lines and the calipers. Previous owner replaced the brake lines but did not replace piston seals, so no information on caliper history

Any thought from all you smart guys to isolate the problem ? Probably is a piston seal but can not see leaks, hate to throw parts at it.

many thanks

Joe

Edited January 21, 2014 by Devildog

[Gunslinger]

If you see no obvious external leaks, it could be leaking back into the brake booster. That's not unknown in different make cars.

[WayneC]

See the schematic below (which illustrates a leak in the front brake line... ignore that leak for this discussion).

Seems to me that if only the front M/C reservoir loses fluid, then it should not be leaking to the booster unit... I believe there are seals on the M/C piston that would have to be leaking from either both (front & rear) chambers, or the rear chamber only, in order for fluid to leak through to the booster. I suppose it would be possible for the front reservoir to empty first, and then the rear, if all the piston seals were leaking.

Normally the front (smaller) reservoir services the rear brakes, so you might want to trace the rear brake lines looking for leaks rather than the front lines. You may also need to remove the rear drums to look for fluid that got past the brake cylinder seals inside the wheel (although you may see traces of the leak externally at the inside rim of the drum, or damp lines running radially out on the inner tire sidewall).

Edited January 21, 2014 by WayneC

[Gunslinger]

Have you pulled the rear drums to check the wheel cylinders and that one of them isn't leaking? One thing I haven't seen mentioned is the larger chamber in the master cylinder energizes the front disc brakes...it's the rear chamber on the Avanti. Since it's the front smaller front chamber leaking, it follows you have a leak in the rear brakes. The fluid is probably leaking from one side or the other and the brake shoes are probably soaked, which will require replacing the rear brake shoes. You'll need a complete rear brake rebuild.

If you still would like to check to see if the master cylinder is leaking into the booster, one way to check is to unbolt the master cylinder and pull it away without disconnecting the brake lines. Then take a long white nylon cable tie and stick it into the booster. If it comes out with fluid on it, you know the answer.

[Devildog]

You guys are good.

OK, I will check rear brakes for leaks, one of my buddies told me the the small front supplied the front calipers (I was too lazy to look at the lines).

Rear brakes were rebuilt by previous owner in past few thousand miles, but I will inspect, probably the problem.

Many years ago (about 50) I had a 54 Chevy with power brakes that apparently was some special order car even had power windows and seats. It would suck the brake fluid from the master cylinder, but it was easy to identify...the vacuum sucked the fluid into the intake and looked like a mosquito fogger. Had not thought of that in many years.

[Gunslinger]

There's rebuilding of the rear brakes and there's rebuilding the rear brakes. Just because someone says they've rebuilt them, it doesn't mean it was done properly. It could be simply that new shoes were slapped on and nothing done with the wheel cylinders...or they were done haphazardly.

I wouldn't be surprised if you find at least one rear wheel cylinder blown out and the brake shoes soaked with the fluid.

[warren55]

I agree, it's most likely a rear wheel cylinder. Having just gone through my rear brakes I can hopefully help with pictures and part #'s.

[Devildog]

Too easy, it was the drivers side rear, fluid on inside of tire.

I had the drums off within the past 500 miles while replacing the parking brake cables. All looked clean and dry with new hardware at that time.

They look like a GM brake similar to on my older Corvettes. Warren, if you have reference numbers for the cylinder rebuild kit that would be helpful rather than sorting thru the auto-parts options.

Thanks again

Joe

[Gunslinger]

The easiest thing is to get the parts from Myer's Studebaker, Nostalgic or SI. You'll know they're the correct parts.

[warren55]

From the information I gleaned at Bob Johnstone's site this is what I bought and they work great. They are 13/16" bore, which is what was in mine. I believe the earlier cars had 3/4" bore cylinders but it appears yours is newer than mine so you should be fine. http://www.amazon.com/gp/product/B000C70H4A/ref=oh_details_o06_s02_i00?ie=UTF8&psc=1

and the other side:

http://www.amazon.com/gp/product/B000C7234W/ref=oh_details_o06_s02_i01?ie=UTF8&psc=1

Edited January 22, 2014 by warren55

[WayneC]

Devildog, my notes say the rear brake cylinder kits are "Lockheed Wagner F8418" ... the "F8418" is likely an EIS industry standard part number that can be from multiple parts suppliers (Federal Mogul, Wagner, Bendix etc).

When I used Warren's link to Amazon, I found I had bought those same cylinders from Amazon back in 2009

and used them on my '80 Avanti.

Edited January 22, 2014 by WayneC

[warren55]

Just remember that there is a left and a right side, 36076 and 36077. The bleeder valve is angled towards the back of the axle.

[Devildog]

Again thanks all of you. I just pulled the suspect cylinder and it is perfect. The cylinder is not scored, no rough spots, etc. The seal cups were new looking and the pistons were smooth with no sign of scoring. The outer seal covers were strong and appeared new. They are 13/16, I will install a new set for the heck of it.

Much fluid on tire, but not that much on the mechanicals (usually a gummy wet mess).

I am suspicious of the flaring on the brake line. It appears line was not cut quite square and flare was a bit shallow, also did not require much wrench force to loosen it (usually tough to loosen them). I filed the flare square and reflared it; hopefully, that is it.

I will report Thanks again

Joe

[Devildog]

Final report:

I reinstalled everything, bled the brakes and tried to force a leak. I saw no fluid.

I could not buy a repair kit locally for these 13/16 wheel cylinder. I used the one I removed, it is like new. I will order one and keep on shelf.

I am 95% sure it was just a leak at the brake line-wheel cylinder fitting. Flare not made correctly and worked loose

Wayne, the number "Lockheed Wagner F8418" is for the older 3/4 inch cylinder. We could not fine one for the 13/16

I cleaned the wheel and tire to remove all the old leaked brake fluid so I can monitor easily for leak.

Thanks again to all of you... my buddy that told me the front small master chamber supplied the front calipers has been shamed into buying beer and lunch.

Joe