EtypeBrakes--fluid gone????

[why]

'67 Series 1 Etype, Got in car to return home and noticed brake pedal was soft and went far down before stopping. Did a few quick pumps no change, went very slow in parking lot and it stopped just fine. Drove to nearby Sbucs looked under and no fluid under car. Opened bonnet and noticed rear resevoir low if not empty. Drove home 5 min and car stopped just fine with long pedal. In garage examined all around under and could not find sign of fluid. Filled empty resevoir, pumped pedal, no change in fluid level, nothing under car. Haynes diagram shows rear resevoir feeding master that then sends it down to the "slave" cylinder under the master that then sends it out to the rear brakes. Front brakes have a separate pipe coming out from this "slave" to the front brakes (other resevoir feeds this cylinder directly). 1) any ideas on where the fluid went? 2)Thought I would just bleed rears to see if doing that somehow shed some light on problem. Looks like a real finger twister to get hose onto bleed screws, maybe taking off the front shock would give better access, any other way? Thanks, Jay p.s. rear calipers the all-stainless ones

 

[Deleted member 8987]

Booster. Sucking it out. Bets. On Jags, the vacuum is to one end of the inlet, when the booster gets full, you get a lot of weird looking (and smelling) smoke out of one pipe.

 

[Brinkerhoff]

Right . And if your using silicone brake fluid it will damage the engine if sucked through it.

 

[why]

Thanks guys will check, is fix new booster or???? Jay

 

[why]

Sorry for ignorance, but...is booster same as "servo" in parts manual. About 6 months ago I put in the "rebuild kit-reaction valve" some new vacuum hose and a new vacuum tank check valve. I just took valve off tank, put coat hanger into tank and got some wetness on end that seemed like brake fluid. Also took hoses off valve and got some fluid wetness from the bottom hose that comes from the triple connector on the other side of engine under the master cylinder. In the Haynes diagram fluid could enter that system from either the master cylinder side of the reaction valve diaphragm or the tandem slave cylinder having a worn something that allows the fluid to leak back into the vacuum chamber of the "tandem slave cylinder." Maybe since I recently messed with the reaction valve that would be the place to look for fluid where it should not be which from scrutiny of valve diagram everywhere should be dry. thanks again for comments, any more much appreciated. Jay

 

[Deleted member 8987]

Sorry for ignorance, but...is booster same as "servo" in parts manual. About 6 months ago I put in the "rebuild kit-reaction valve" some new vacuum hose and a new vacuum tank check valve. I just took valve off tank, put coat hanger into tank and got some wetness on end that seemed like brake fluid. Also took hoses off valve and got some fluid wetness from the bottom hose that comes from the triple connector on the other side of engine under the master cylinder. In the Haynes diagram fluid could enter that system from either the master cylinder side of the reaction valve diaphragm or the tandem slave cylinder having a worn something that allows the fluid to leak back into the vacuum chamber of the "tandem slave cylinder." Maybe since I recently messed with the reaction valve that would be the place to look for fluid where it should not be which from scrutiny of valve diagram everywhere should be dry. thanks again for comments, any more much appreciated. Jay

Servo and booster same, just different nomenclature.
The seal on the end against the booster (servo) cannister is leaking.
Could be wrong way around, or simply perished.
On my Jag, they bolt in from the inside of the vacuum can, so not easy to do. Pain in the butt to get out (remove RF wheel, remove inner wing cover, lean over the wing remove all lines, work the unit out of the hole).
ANY fluid in vacuum can is not god. If you've emptied the reservoir, at least that much. My Jag is specific NO DOT5. MK2 seals are NOT designed for it. If you use DOT5, check with your parts supplier and listen to the answer carefully when you ask about using DOT5.
Check the pushrod end of the master just to be safe for wetness.
It can leak there, but wetness in the canister is a good indicator you have an issue there...at least.
Dave

 

[Geo Hahn]

To check for fluid in the canister I pull off the fitting at the top and use a length of wire as a dipstick to reach to the bottom. If it comes out dry you can move on to the next thing.

...2)Thought I would just bleed rears to see if doing that somehow shed some light on problem. Looks like a real finger twister to get hose onto bleed screws, maybe taking off the front shock would give better access, any other way?

Some remove that shock but I have always been able to work the rear bleeders with a 7/16" wrench that I have ground off excess material to gain more swing room:

FWIW -- I switched the E-Type to DOT5 as soon as I got it as I have used DOT5 in all my British Cars for many (15+) years with no problem. But if you have doubts then by all means stay away from it.