Front brake mush
Thread Starter
|
New User
Joined: Mar 2004
Posts: 6
Likes: 0
From: Southern Calif.
Front brake mush
I have an early 94 F350 deisel that I'm having a problem with. I changed the front disk pads without opening up the hydraulic system. I just compressed the pistons because I had just changed all the fluid during a clutch master replacement. After I finished the brake job the truck stops fine but the pedal feels mushy and eventually goes to the floor. I had the same problem on my 1987 F250. I changed the brake master cylinder on that one without any improvement. Did I forget to do something?
Junior User
Joined: Mar 2004
Posts: 97
Likes: 0
From: qualcum beach bc
i was told once that the rear brakes set the peddle hight
but spongey peddle with no leaks could could be air or a bad master cylinder
when mine went truck would stop and then peddle would go to the floor lots of fun in the big city at rush hour
but spongey peddle with no leaks could could be air or a bad master cylinder
when mine went truck would stop and then peddle would go to the floor lots of fun in the big city at rush hour
Senior User
Joined: Oct 2003
Posts: 409
Likes: 0
From: New York
Welocome to the best site online for ford trucks
mushy feeling can only be casued by air in the line. or a bad master cylinder. first check the level of brake fluid in yar resvior. if thats good next look carefully around yar rotors for any damp spots. its posiible while ya were doing the brakes ya bent kinked or twisted etc a line and got a very small leak. if no leak set yar parking brake then release. see if brakes are still mushy. if so then ya have to bleed the system. bleed it good and long brake fluid is cheap and the air buble could be up by the porptioning valve from when ya compressed the slave cylinder/calipers in. good luck and let us no
mushy feeling can only be casued by air in the line. or a bad master cylinder. first check the level of brake fluid in yar resvior. if thats good next look carefully around yar rotors for any damp spots. its posiible while ya were doing the brakes ya bent kinked or twisted etc a line and got a very small leak. if no leak set yar parking brake then release. see if brakes are still mushy. if so then ya have to bleed the system. bleed it good and long brake fluid is cheap and the air buble could be up by the porptioning valve from when ya compressed the slave cylinder/calipers in. good luck and let us no
Senior User
Joined: Mar 2004
Posts: 246
Likes: 0
I also had one that the power booster went bad and did som really screwy crap. some times it had way to hard a pedal and no brakes and then ti would go to super soft pedal and marginal brakes and would act like it bleeded down. Also check the lines on the rear axle. Notorious for small pinholes rusting in them.
New User
Joined: Mar 2004
Posts: 24
Likes: 0
From: Rio Rancho
I have the same problem on my 93 F350. I just bought the truck with soft brakes. We first thought it was a master cylinder and replaced it, no change. We tried 3 more with the same results. We then checked the rear drums and replaced the shoes, drums were fine, no help. then we checked the vacuum pump and vacuum, that was good. tried a replacement booster, no change (took it back off). replaced the anti lock control valve no change (had to keep that). also we were bleeding after every component change. last weekend i replaced front pads that were worn past half way, no change. Right now I am thinking we didn't get all the air out of something. I have looked for leaks in the lines and havent been able to find any traces. I am going to have the brakes bled at a shop next. also tried pulling the fuse on the anti lock with no change, even disconnected sensor and control valve with no change.
Last edited by Dennis690; Mar 22, 2004 at 10:59 PM.
Thread Starter
|
New User
Joined: Mar 2004
Posts: 6
Likes: 0
From: Southern Calif.
Apparently changing any of the brakes can put air in the line (I knew that) but I had always gotten away with bleeding only the changed brakes. I learned that on the F series you have to bleed long and hard on the rear drums before the air gets out and peddle pressure returns to normal. I had the dealer do it but they must have been lazy because I repeated it, even parked the truck on a incline with the rear end higher to get the last of the air out. Brakes are much better. Thanks for all your confirmation.
Senior User
Joined: Jul 2006
Posts: 129
Likes: 0
I would take a look at the back drum brakes. I did some work on the front brakes also and the pedal was mushy and would slowly go to the floor if held. I too replaced the master cylinder, still didn’t work. It’s hard to get the rear brakes right by just using the adjuster and doing the move them and check them method. If you can get a “drum brake caliper” measure the inside of the drums then move the shoes to match the other side of the caliper. If you can’t get one put the rear end up on jack stands and adjust the adjuster till they start to drag then back off a little and take it for a drive. That’s the way I did mine and the brakes are fine now. Anyhow I’d give that a try first…
Trending Topics
Thread Starter
|
New User
Joined: Mar 2004
Posts: 6
Likes: 0
From: Southern Calif.
Thanks for your coments. I bought new shoes and was about to pull the drum. I'll follow your suggestion and adjust the shoes so that there is light resistance. Why coudln't the Ford dealership figure this out. They must see hundreds of trucks each month?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Post Fiend
Joined: Nov 2004
Posts: 5,638
Likes: 1
From: Manitoba
Never put......... Never seize on the lug nuts, light oil at the most.
The 92-94 trucks require the brakes be bled...RT rear, LT rear, RABS valve, FR right, Fr left....... filling reservoir as you need.
Oversized rear drums will cause problems .....always have them checked before replacing shoes and before/after turning.....
Try backing up and adjusting the rear brakes or always use your park brake and it will keep it adjusted. Out of adjustment rear brakes require the M/C push more fluid to overcome the out of adjustment distance...........mushy pedal.
The 92-94 trucks require the brakes be bled...RT rear, LT rear, RABS valve, FR right, Fr left....... filling reservoir as you need.
Oversized rear drums will cause problems .....always have them checked before replacing shoes and before/after turning.....
Try backing up and adjusting the rear brakes or always use your park brake and it will keep it adjusted. Out of adjustment rear brakes require the M/C push more fluid to overcome the out of adjustment distance...........mushy pedal.
Senior User
Joined: Jul 2006
Posts: 129
Likes: 0
PLC7 do you do brakes? If so how do you guys set the shoes to the drums, do you use a caliper type devise? I've seen a couple of the old ones around and they look like they'd work pretty good for setting up the shoes?
Last edited by 93_E_350; Nov 14, 2006 at 06:06 AM.
Senior User
Joined: Jul 2006
Posts: 129
Likes: 0
What’s wrong with never seize? I’ve used it on every vehicle I’ve ever owned. I’ve twisted lug wrenches, and broken 1/2” breaker bars on lug nuts with out – never again…
I tried the backing up too for a half hour, I wound up putting the rear end on jack stands adjusting the brakes till they dragged a little then backed them off so the wheels turned free then did the back up adjust. There used to be a little shop in the town where I used to live in that did a great job on brakes among other things. Now I’m back to the DIY cycle… I hate doing brakes and exhaust systems, up here the rust really screws that stuff up!
I tried the backing up too for a half hour, I wound up putting the rear end on jack stands adjusting the brakes till they dragged a little then backed them off so the wheels turned free then did the back up adjust. There used to be a little shop in the town where I used to live in that did a great job on brakes among other things. Now I’m back to the DIY cycle… I hate doing brakes and exhaust systems, up here the rust really screws that stuff up!
Post Fiend
Joined: Nov 2004
Posts: 5,638
Likes: 1
From: Manitoba
First like Polish stated.......if you ever change a M/C always bench bleed them first...... some even come with fittings with hoses attached to recirculate the fluid back into the reservior, don't throw those puppy's away they are great tools.
Those old caliper things were great, but there are so many tools today. The guys at the shop just install the drum, if it is easy going on they take it off and adjust the shoes until it is just draging on install. (This is on a turned/dressed drum of the correct diameter) The brakes will loosen in minutes of driving and require backing up daily for a few days.
Anytime the pedal is low just keep.. back up-stop hard, go ahead, stop and do it all again until your satisfied. The adjusters must be working and installed the right way.
Note most pictures of the rear brakes show the Left side with an arrow forward..... ensure when you do the right side you install as per the "arrow" to front. Almost got to look through the picture from the back if you know what I mean.....
Those old caliper things were great, but there are so many tools today. The guys at the shop just install the drum, if it is easy going on they take it off and adjust the shoes until it is just draging on install. (This is on a turned/dressed drum of the correct diameter) The brakes will loosen in minutes of driving and require backing up daily for a few days.
Anytime the pedal is low just keep.. back up-stop hard, go ahead, stop and do it all again until your satisfied. The adjusters must be working and installed the right way.
Note most pictures of the rear brakes show the Left side with an arrow forward..... ensure when you do the right side you install as per the "arrow" to front. Almost got to look through the picture from the back if you know what I mean.....