Brake problems!!!! Please Help!
Thread Starter
|
Senior User
Joined: Feb 2002
Posts: 291
Likes: 0
From: Oregon
Brake problems!!!! Please Help!
1991 F-250 4x4.
I was driving and they worked fine, then all of the sudden they didnt work and the brake light came on. The fluid did not leak out. The pedle is still firm and doesnt go to the floor. It felt like the back ones worked a little.
So I changed the master cylinder today and bleed all the air out of the system. Now the pedle is firm again and I thought I fixed it, untill I took it out for a drive, and its the same thing. The pedle is hard, there is no air in it. And the back brakes work, but nothing from the front.
Whats wrong?
Thanks,
Lars
__________________
I was driving and they worked fine, then all of the sudden they didnt work and the brake light came on. The fluid did not leak out. The pedle is still firm and doesnt go to the floor. It felt like the back ones worked a little.
So I changed the master cylinder today and bleed all the air out of the system. Now the pedle is firm again and I thought I fixed it, untill I took it out for a drive, and its the same thing. The pedle is hard, there is no air in it. And the back brakes work, but nothing from the front.
Whats wrong?
Thanks,
Lars
__________________
Junior User
Joined: Nov 2003
Posts: 98
Likes: 0
From: Talladega, AL.
Sounds like you have a bad vaccum pump. If the belt is on it, pull a line off and give it the old test. You should feel the vaccum. You can get them at the parts store, but must have a puller to remove and replace the pully. Don't attempt it with a hammer.
Junior User
Joined: Nov 2003
Posts: 98
Likes: 0
From: Talladega, AL.
You should have around 14 to 16 inch pounds, if you have a gauge to place in line. You will see in a hurry.
I have experienced this many times. You will have a hard low pedal. Brakes are there, but you have to mash HARD to get them.
With the 91, you are "blessed" with the E 4 OD. The older ones with the C 6, needed 13 inches to the moudulator, or it would never shift right, making you think the transmission was bad.
Good Luck!!
Les
I have experienced this many times. You will have a hard low pedal. Brakes are there, but you have to mash HARD to get them.
With the 91, you are "blessed" with the E 4 OD. The older ones with the C 6, needed 13 inches to the moudulator, or it would never shift right, making you think the transmission was bad.
Good Luck!!
Les
Junior User
Joined: Nov 2003
Posts: 98
Likes: 0
From: Talladega, AL.
It's possible, but check the vaccum first, that is the easiest. Also see if the vaccum line going to the booster is free. Sometimes with age, the inner walls of the line will collapse. Also look for possible leaks (cracked lines)in the vaccum system. Heat and years take their toll on them.
Thread Starter
|
Senior User
Joined: Feb 2002
Posts: 291
Likes: 0
From: Oregon
The Vaccum is 10-12 both at the pump, and at the booster.
Is this too low? If it is what is the next step? Change the pump?
Also I was looking for the valve in the brake line and couldent find it. Is it in the master cylinder?
Thanks for your help.
Lars
Is this too low? If it is what is the next step? Change the pump?
Also I was looking for the valve in the brake line and couldent find it. Is it in the master cylinder?
Thanks for your help.
Lars
Trending Topics
Junior User
Joined: Nov 2003
Posts: 98
Likes: 0
From: Talladega, AL.
On the E series the valve is underneath on the frame. My experience with them has given a disapearing pedal. You can pull the spring out and see if it makes a difference. That valve is kind of pricey.
The book says 15-19 inches of vaccum at idle in neutral. If you have only 10-12, you are too low.
Les
The book says 15-19 inches of vaccum at idle in neutral. If you have only 10-12, you are too low.
Les
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Post Fiend
Joined: Jan 2001
Posts: 5,121
Likes: 1
From: Springfield, VA
On the E series the valve is underneath on the frame. My experience with them has given a disapearing pedal. You can pull the spring out and see if it makes a difference. That valve is kind of pricey.
When you say "disapearing pedal" do you mean that it gets soft and goes away? I have changed my master cylinder out, bled the lines about a dozen times (gravity and using my helper to bleed), bled the RABS and master cylinder several times for each), adjusted the rear shoes, put new calipers and pads up front and I still have no good brakes. I checked the vacuum and am getting good pressure. I have brakes, but I need to pump the pedal 1 or 2 times before they get firm, then next stop light they are soft again. Got any clues for me? Oh, and I have checked for leaks, ther are non that I can see.
If I can't figure it out soon, next stop is the brake shop. I know that brake fluid is chaep, but I have gone thorugh about 1 1/2 gallons of fluid so far (my wife thinks I am drinking the stuff, cause I always need to run to the store) and no luck.
Thread Starter
|
Senior User
Joined: Feb 2002
Posts: 291
Likes: 0
From: Oregon
I just took my truck to the brake shop. 198 bucks for the air pump, and 90 bucks labor to install pump and power bleed. They might get it done today.
I wish I would have taken it there first instead of putting the new master cylinder on for nothing.
Lars
I wish I would have taken it there first instead of putting the new master cylinder on for nothing.
Lars
Junior User
Joined: Nov 2003
Posts: 98
Likes: 0
From: Talladega, AL.
Karl,
On the antilock valve, there is a 15/16 nut (cap) remove that and pull the spring out. Replace the nut. See if that helps.
Lars,
The pumps are 107 here in Alabama. Pretty easy swap. At the price your shop is charging, you could have bought the pulley puller/installer set and had some change left.
Les
On the antilock valve, there is a 15/16 nut (cap) remove that and pull the spring out. Replace the nut. See if that helps.
Lars,
The pumps are 107 here in Alabama. Pretty easy swap. At the price your shop is charging, you could have bought the pulley puller/installer set and had some change left.
Les
Thread Starter
|
Senior User
Joined: Feb 2002
Posts: 291
Likes: 0
From: Oregon
Thanks for all your help, I think the shop gave me a good price on the pump because I called 3 differant auto parts stores here in Oregon and they were all over $215 just for the pump!
I got the truck back and it works great, $280 bucks.
Lars
I got the truck back and it works great, $280 bucks.
Lars