1badFB

iTrader: (1)

Ok, so I have had my car parked outside over the winter. It gets prety damn cold up here just so you guys know the situation (has been colder than -40C).

Anyways, It finally got warm enough that I could go out and do some wrenching, and while I was pulling the ol beehive cooler out today I notice that the brake fluid reservoir is completely empty. I am almost sure it was right full when I put it away and the brakes worked fine. Now there is no fluid and the pedal goes to the floor..What gives.

I took a peek under the car and I cant see any fluid that has leaked anywhere, and the inside of the wheels show no sign of a leaky caliper.
Anyone have any idea where to look...seeing as the fluid myseriously vanished???
Seems quite unusual.

The car is a 1985 GS w/ stock open diff+drums still on there.

Thanks

woodonastick

iTrader: (1)

possibly a leak. brake fluid takes paint off real quick too, so look for paint looking brittle and crumple? that plus brake fluid evaporates(? is that the word im looking for?) in a night.

1badFB

iTrader: (1)

Oh, its definately leaking..I guess I should really give the whole system a good look over, but since it sat so long I have to bleed the bad brake system just to be able to pump the fluid out to find the leaky part.
There really doesnt seem to be any indication of fluid dripping off the car or into the wheels, so I was just wondering if there is a suspected place they go. Im almost gonna bet on a mounting point or through the fender or something. Somewhere that the dirty car hid the fluid.

I guess its just another job to add to the list haha!

misterstyx69

iTrader: (142)

Just from Workin with Drum brakes in the past I would be checking the wheel Cylinders.But right now since you don't have any Fluid showing in the reservoir,it's Crapshoot..you can Only Guess.If I were doin it..I would put some fluid back into the system and start to get pressure into the Brakes. Have all the wheels Off the car.The car on Stands.Get a Buddy to Pump the brakes up while you do an Inspection,A thorough inspection..It should get you some results..I know it's not much.but it's a Start..Good Luck.

trochoid

iTrader: (6)

Fill it back up with fluid and start bleeding. If the wheel cylinders and calipers aren't leaking, pull the carpet back under the pedals and look for soaking.

1badFB

iTrader: (1)

Can that happen with the brake...doesnt the booster isolate it??

Rogue_Wulff

I suspect the master cyl. Prolly leaking into the booster. Look at the booster where the master bolts on.
Mine does the same thing. I learned to pump the pedal a few times after shutting it down, when the temp is gonna drop below freezing. I'm just nursing it till the warmer weather gets here, so I can replace the master.

1badFB

iTrader: (1)

So, today I went out and fired the car up to move it a bit.
It appears as if the brakes werent completely out, just wouldnt engage until the pedal was very close to the floor.
I had decided that before I safety the car I would give the whole brake system a good fixing up. Napa only had the front pads in stock but the rear shoes are on order.

I put the new front pads in today, and the brake seems to feel better than ever now. I am questioning the master cylinder as a problem now because of the effect the front brakes had on the problem.
I was thinking, and for the fluid to leak out the back of the master cylinder wouldnt it have to get by the piston ring/seal? If this is true wouldnt it allow fluid to pass much easier when I apply pressure to the brake?...When I do it seems fine, so Im sorta confused at this point.

Maybe I just didnt realize the brakes were so bad when I drove it home... I think Ill just keep an eye on the level of the fluid and watch out for any problems to come. I dont really wanna drop a pile of money on the master cylinder right now..because after its safetied I have a disk brake rear end to go in.

Anyone else have any idea why such a thing could happen?...

trochoid

iTrader: (6)

My bad, I was confusing the brake master with the clutch master. It's the clutch master that can leak into the interior. If the brake master is bad, replace it, changing the rear end will have no affect on the master if it's changed out now, other than a rebleed.

Since you have drum brakes now, how many clicks does it take for the e-brake to engage? The FSM recommends 4-5 clicks, if you are pulling it many more clicks than that, the rear shoes may need adjustment and that may be the cause of excessive pedal travel.

1badFB

iTrader: (1)

Its fine now, but before I got at it and did the front pads the fluid was way low and the pedal was as well. The rear shoes will be replaced as soon as they come in.

Maybe I just didnt check the brake fluid and it was like that when I bought it........


Trochoid, dont forget that the disc brake rear ends and drum brake rears have different master cylinders. I dont really want to buy it twice, I guess I could just buy the disc one and use it to get me through the safety with the stock rear.
.... at this point thats all Im worried about. After its safetied the rear end with the craziest clutchpacks and 4.88's goes in...I just think Im already pushing it when it comes to the safety with my exhaust.

trochoid

iTrader: (6)

I'm running a drum master with a disc lsd in the widebody. Not entirely sure what the differences are between them, I do know some of it is in the proportioning valve too.

fluffysheap

I've got the same thing as trochoid, as it turns out. The pedal action is significantly stiffer and there seems to be more travel, but it basically works ok.

Also I just about need to use my jack to get enough force on the parking brake handle

Rogue_Wulff

The difference is a residual pressure valve inside the master. This holds a small amount of pressure in the drum setup. It can easily be removed. Usually located either under a blind plug on the master, or behind the large plug where the rear line hooks to the master. Both styles have been used, so it's a crapshoot.
The residual pressure valve really doesn't affect the rear disc.
According to the parts fische, the proportioning valve is the same.