Brake questions

chillman88

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Hey all,

My 91 Crew Cab Dually has "questionable" power assist for the brakes. I'm trying to figure it out and I'm afraid I might have.

I tested the Vacuum at the Tee on the firewall and I had 5-10. I tested it at the pump (line direct from pump to gauge) and have 20 at idle.

I was under the dash today and I noticed a slight hissing sound. I pressed the pedal by hand and it stopped for a moment before resuming the hiss. It was a press and hold, not press and release.

I'm thinking my booster is leaking. What are your thoughts?

I want to do a hydroboost swap but it isn't in the cards right now. I'd consider it if I wasn't going to have to change out the pedal too, I found a used booster for $60.

I also will be installing an old hydraulic actuated trailer brake controller and need to order a tee for the line. Is the rear line at the master cylinder for the rear brakes? I think I read it's 7/16 thread but I want to get the right part the first time.

Thanks!
 

IDIBRONCO

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No The rear brakes are at the front of the master cylinder. The easy way to remember is that the front brakes have the bigger of the two reservoirs because they do have most of the stopping power.
 

chillman88

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No The rear brakes are at the front of the master cylinder. The easy way to remember is that the front brakes have the bigger of the two reservoirs because they do have most of the stopping power.

I knew the reservoir trick but I couldn't tell from looking at mine. Thanks!
 

Clb

Another old truck
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If you want to pay the ride for my 44k unit off my 93(going hydroboost) its still working fwiw.
Its yours with the mc.
Pm me
 
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