1976 Ford 600 brake problems
Thread Starter
|
New User
Joined: Jun 2008
Posts: 3
Likes: 0
1976 Ford 600 brake problems
Hi Everyone,
I have a 1976 Ford 600 truck and am having trouble with the brakes. When I apply the brakes the hydro vac activates the boost valve and allows the air pressure to boost, I can here the air as the intake hose is behind the drivers seat. When I take my foot off the brake the air is still giving boost (as I can here it) . When I stop the truck and open the bleed on one of the wheel cylinders there is brake fluid pressure as I can here the brakes release.
When start the truck and apply the brakes ...they work O.K. until the system pressures up and I have the same problem. It seems that the system won't depressure enough to allow the boost valve to fully close.
I would appreciate anyones input.
Thanks, Robert,
I have a 1976 Ford 600 truck and am having trouble with the brakes. When I apply the brakes the hydro vac activates the boost valve and allows the air pressure to boost, I can here the air as the intake hose is behind the drivers seat. When I take my foot off the brake the air is still giving boost (as I can here it) . When I stop the truck and open the bleed on one of the wheel cylinders there is brake fluid pressure as I can here the brakes release.
When start the truck and apply the brakes ...they work O.K. until the system pressures up and I have the same problem. It seems that the system won't depressure enough to allow the boost valve to fully close.
I would appreciate anyones input.
Thanks, Robert,
Junior User
Joined: May 2006
Posts: 72
Likes: 0
I also have a 76 F600 with probably the same setup. Without thinking this through (and given that I haven't completely learned about the hydro-vac inner-workings, etc.) One quick thought is to try to open the bleeder valve on the hydrovac unit itself. If that releases the pressure then it will split your search in 1/2 - from the there up to the master cylinder or from there out to the wheel cylinders. Just a quick thought. Let us know what you find.
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
Is it supposed to have some sort of filter over the inlet? If it is anything like the foam filters used in the mid-to late-70s truck brake boosters, it's probably deteriorated and might have jammed the valve.
Thread Starter
|
New User
Joined: Jun 2008
Posts: 3
Likes: 0
I finally figured out what the problem was. I took the big drum apart (i didn't realize it contained a diaphram which activates the plunger or cylinder that provides the boost to the whole system). There was rust etc on the lip of the diaphram and as a result a leak ...and therefore a partial vacuum . I cleaned the drum, now everything works as it should.
Thread
Thread Starter
Forum
Replies
Last Post
Robert6401
1999 - 2003 7.3L Power Stroke Diesel
10
Apr 16, 2018 02:32 AM
94FSuperDuty
Brakes, Steering, Suspension, Tires, & Wheels
6
Dec 3, 2005 11:15 PM
