I have a 77F 600 that I’ve been working on since I got it almost 4 years ago. I redid all the brake lines got the motor freed up. Repaired some rust. Having a problem with the water pump, but that’ll be addressed later on switch the rear end. But I’m having a lot of trouble finding a brake booster. I’ve seen some other posts on here. No one makes a new one more. At least to my knowledge. I see everyone saying. To convert the master cylinder and the booster to a firewall booster problem is I have a brand new master cylinder, I know it’s the booster because the internal seal is failed and when the engine is running, it’ll suck the fluid out of the booster itself and plumb it into the engine I have to get it to stop before I wanna do any more work to it and this has been my bind for the past year thanks for any Help

 

Welcome to FTE!

I moved you here because this is the forum for trucks that size.

OK so your current booster is on the frame under the cab?

And it's sucking brake fluid to the manifold?

The brand new master--is that the OEM firewall mounted master that sends to the frame mounted booster?

Pictures of the setup may help.

Rebuids and kits are getting hard to find but not impossible for the frame mounted units.

Firewall mounted replacements are also a thing as Ford offered those on some trucks as OEM.

 

I have a 78 F-600 , with a single line firewall mount master cylinder , I was getting my boosters from NAPA ( Cardone ) & the first one lasted about 5 years & close to $ 200.00 . then they raised to $ 600.00 I installed a firewall mounted two line MC/ booster & proportioning valve from Battle born brakes . No regrets yet good luck

 

You mentioned that in this thread:
https://www.ford-trucks.com/forums/1...1977-f600.html
where you said:
Can you find your old post and link it here?

 

don’t you have to switch to a new master cylinder though or can you keep the factory one, in the process of repairing everything I had to purchase a new master cylinder, it was around $500 not something I’d just want to throw away as I can’t return it now or sell second hand for next to nothing

 

Ouch. I bought a new Dorman replacement master cylinder, via Amazon, for my '73 F600 in Jun2024 for under $80. I used Dorman M36127, which is not an exact fit (it's listed for a '72 F600) and an for $14, as the pushrod needed to be a bit longer. It's been working well for a year. Amazon lists a lot of new MCs for our trucks, but finding one that's the exact fit can be dicey (Dorman does not list one on their site for my '73) and Ford used so many different versions for the various models. But $500, ouch.

Yes, the Battle Born kits have you swap out to a new dual-circuit master cylinder. It's an improvement that was required for all road-going passenger vehicles sold in the US in 1967, I believe. Hydraulic failure of once brake circuit still maintains operation in the other. It's a really good idea. From what I can see in the MPC, all the B-series (buses) got the dual hydraulics from at least '73-on, but the trucks mostly didn't for many years.

 

I had the same problem with my 79 F600. I was able to use O'Reilly's to send my booster off to get rebuilt. There is a parts company, Cardone I think, that will rebuild parts but you have to go through O'Reilly's.

 

I will wave you off from Cardone; I had three bad rebuilt FT distributors from Cardone. The best of the three was one I ordered through O'Reillys, and its vacuum governor section doesn't work, which was the reason I was replacing my original disty in the first place. Read this post and the one after it for details and pictures of the crap sold under the Cardone banner.

Anybody but Cardone.
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O'Reilly's bought up three local auto parts chains in the PNW (Checkers, Al's, Schucks) over the decades, and I kind of held that against them for a long time, but my local O'Reilly's often does a better job for me than the local NAPA, and the Autozone across the street, so they're kind of my default FLAPS these days. But not Cardone, no.