Hi all, I'm hoping you guys can help me out. I have a 1949 Rocket 88. She's my pride and joy but has developed a worrying brake problem. They work fine until you have braked down a long hill and then you realise that your foot is to the floor and you aren't slowing down much.
The car has been layed up over the winter and I have had to top up the fluid as the level seems to have dropped a bit. I can't find a leak anywhere although I've not stripped each brake down. All cylinders were new a few years ago. The car is still on drums all round with the addition of a brake booster under the hood. could it be down to the master cylinder needing a rebuild? The servo says Delco moraine but not sure what it is out of originally.
Any help is much appreciated.
Stuart.

 

This is what I have. No idea what it is off.<br/>Would the best way to tackle this to bleed the whole system and try it before I do anything more involved?

 

If your having to add brake fluid often you have a leak. Fix, adjust, and bleed the system.

 

Most likely if no leaks are seen it's bleeding back through the master cylinder and returning to the fluid sump / reservoir.

I also don't think I've seen that booster and master before but If mine I would probably replace it with a dual reservoir system and booster. Maybe something out of a S10 or like brake system. That master looks as old as your car... Tedd

 

Looks like one off a '64-6 A-body.

 

It looks like a 65 ? or so master cylinder .
If it's losing fluid , with no apperant leaks , then it may be leaking out the back of the master into the booster unit .

 

Thanks for the advice everyone. I'm going to have a better look at it tomorrow and check each wheel cylinder for leaks. I have a suspicion that it might be leaking out the back of the master cylinder although I can't see any evidence so I will slit those parts and take a look. I'm wondering if the seals in the master cylinder might be letting fluid pass but then again that would probably mean that the brakes would be poor every press rather than after a few applications.

A new dual circuit system would be nice but I have the car advertised at the moment so I don't want it out of action for too long while I'm getting parts. Is the bolt pattern between the booster and the master cylinder an industry standard? I'm just thinking how easy it will be to find a replacement that will fit. Of course I'd be happy to fit a new seal kit but I'd need to be sure what master cylinder I have but I haven't a clue.

 

The Fooeymobile don't need no brakes.

 

If the MC is leaking and you see nothing, it could very well be that the fluid is going into the tank of the vacuum booster.

Do keep us posted.

 

Update!
So I split the master cylinder from the servo and I saw a tiny bit of moisture. Hardly anything though. I stripped each brake drum and found that the front left was wet behind both seals on the wheel cylinder and a small pool of fluid in the wheel bearing back plate/shield that has a little catch trough presumably for bearing greece but it did a good job of holing the fluid.
Ordered a new cylinder from Fusicks and I will bleed the whole system and hope for the best. I would be happy to fit a seal kit to the MC if I knew what to order but its a part of 'unknown origin' so I'm a bit stuck to know what to order.

 

Looks like you found the source of your trouble, if you have a good pedal after replacing the faulty parts it might be an idea not to go looking for trouble - if it ain't broke, don't fix it.

Whereabouts are you?.

Roger.

 

If your master cylinder is leaking/weeping at the rear seal, it needs to be rebuilt or replaced. See if there is a part number on it somewhere.