1971 F600 brakes

[1970Custom]

Trying to figure out the brake system on the truck.

Replaced the master cylinder, but dont have any brake pressure but no leaks to be found.

It has the booster under the cab? Can somebody explain the system to me, please.

 

[Blue Goose]

No pressure or no pedal?

 

[DNFXDLI]

I'm looking in the 71 shop manual and it does say frame mounted

 

[DNFXDLI]

Have you confirmed you have vacuum to it?

 

[1970Custom]

Brad, step on the pedal and it goes to the floor...


Duncan, can you tell me the parts attached to the booster? Or the parts not common with the pickups?

 

[DNFXDLI]

Parts look different from what I can tell...also, it seems there are a few different choices. Do you want me to scan and post them?

 

[1970Custom]

Could you please.

 

[DNFXDLI]

Gimme a few minutes

 

[DNFXDLI]

 

[1970Custom]

Looks to be the first one. Now if Brad can tell me how it works....

Thank you Duncan.

 

[DNFXDLI]

Do you have vacuum going to it?....that would be the first thing I would check.

 

[DNFXDLI]

Looks to be the first one. Now if Brad can tell me how it works....

Thank you Duncan.

Anytime

 

[1970Custom]

Do you have vacuum going to it?....that would be the first thing I would check.

I have no pedal pressure, I pumped till my leg was sore and got nothing.

 

[DNFXDLI]

I have no pedal pressure, I pumped till my leg was sore and got nothing.

I got that...but isn't there a line that supplies the booster with vacuum?
On the other hand, if there is no vacuum, the pedal should get stiff....hmmm.

 

[Blue Goose]

Did you have the engine running while bleeding the system?

 

[1970Custom]

Did you have the engine running while bleeding the system?

Haven't even attempted it yet, any other time I've replaced a MC I had some pedal pressure, and coupled with me not totally understanding the system I figured I'd ask beforehand.

 

[Blue Goose]

I've always had to have the engine running creating vacuum and thus activating the hydro-vac...

 

[DNFXDLI]

I've always had to have the engine running creating vacuum and thus activating the hydro-vac...

That would make sense

 

[1970Custom]

Okay, can you explain how the system works though? I don't fully understand it.

 

[DNFXDLI]

http://www.stovebolt.com/techtips/bendix/erickson/