Hydro boost leaks back into the cab

[MOguy]

I have a 1979 one ton with hydro boost. It leaks back into the cab. The back brakes work fine but once the fluid leaks out of the reservoir for the front bakes (into the cab) I have no front brakes.

Is there a rebuild kit or replacement parts to fix this?

 

[Honky Kong jr]

Your getting brake fluid or PS fluid in the cab?

 

[MOguy]

Your getting brake fluid or PS fluid in the cab?

brake fluid.

 

[Honky Kong jr]

Hmmmm?

 

[MOguy]

I will take some pics.

From how it looks to me the fluid leaks out the back of the booster where it mounts into the firewall. It only drains out of the reservoir that feeds the front brakes. The back brakes work just fine.

 

[Honky Kong jr]

I will take some pics.

From how it looks to me the fluid leaks out the back of the booster where it mounts into the firewall. It only drains out of the reservoir that feeds the front brakes. The back brakes work just fine.

Maybe I'm missing something but I don't see how brake fluid is getting threw the hydraboost unit. I can see PS fluid leaking out there and maybe one of your front brake lines is leaking. Which is common (brake lines leaking that is)

 

[MOguy]

Maybe I'm missing something but I don't see how brake fluid is getting threw the hydraboost unit. I can see PS fluid leaking out there and maybe one of your front brake lines is leaking. Which is common (brake lines leaking that is)

I can fill the reservoir for the brakes and it won't take long for it to be empty and fluid in the cab. Nothing is leaking in the engine compartment.

 

[highdesertrange]

it's impossible for brake fluid to leak into the cab with a hydraboost. your brake fluid is going somewhere else. also your hydraboost is leaking. highdesertranger

 

[Honky Kong jr]

it's impossible for brake fluid to leak into the cab with a hydraboost. your brake fluid is going somewhere else. also your hydraboost is leaking. highdesertranger

That's what I was thinking.

 

[MOguy]

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I fill it at the beginning of the day and by the end of the day I see this and a puddle of fluid in my cab. I topped of the power steering when I bought the truck and it is still full.

 

[highdesertrange]

the problem though is there really not a pathway from the master cylinder to inside the cab through the hydraboost. if it takes only a day to happen that's a huge leak. leave the brake lines attached and split the master off the booster fill the master up if what is happing as you describe you should see fluid leaking out the master. I still can't see it going through the booster. highdesertranger

 

[MOguy]

the problem though is there really not a pathway from the master cylinder to inside the cab through the hydraboost. if it takes only a day to happen that's a huge leak. leave the brake lines attached and split the master off the booster fill the master up if what is happing as you describe you should see fluid leaking out the master. I still can't see it going through the booster. highdesertranger

Thanks everybody.

I will have to dig into it. It in the reservoir, it gone and in the cab. Not sure what happens in between.

 

[HotRodPC]

I'm going with a bad master cylinder for 100% certain. I'd replace that first. Then see what happens. I'd expect you'll at least have front brakes and if the fluid in the cab floor quits then all is well. If you still have fluid on the cab floor, then I consider a reman booster too.

 

[MOguy]

I'm going with a bad master cylinder for 100% certain. I'd replace that first. Then see what happens. I'd expect you'll at least have front brakes and if the fluid in the cab floor quits then all is well. If you still have fluid on the cab floor, then I consider a reman booster too.

I think I will give that a shoot. Pretty cheap and not too much work.

 

[MrMarty51]

Be sure to bench bleed the master, then, after getting the master bolted up, start the lines into their ports, then, have someone push the pedal down and hold it while You tighten the fittings. That will save You a bunch of brake bleeding.