1995 Explorer Brake Fade

[sclime]

Hi! I am new to this forum, but not to other Ford forums. I am an active member of F150 Online, but also have an Explorer I am currently working on.

Last fall I replaced both the front hub assemblies due to bad bearings. Drove it all winter and this spring replaced all four sets of brake pads and rotors. This Explorer has 4 wheel antilock disc brakes and is a 2 door 4X4.

The brakes seemed to work ok for a couple months, but then seemed to fade upon initial depression of the brake pedal. I replaced the master cylinder and last night the brake booster. I have good vacuum and the initial test for the booster would indicate it is ok.

When I drive it, and slowly apply brake pressure, the pedal sinks to the floor. If I hit the pedal quickly, it has great pressure and I can even hear the antilock system kick in. When I initially hit the brakes hard, it stops great, but if I lift off the pedal and slowly reapply pressure, the pedal sinks to the floor.

I have also bled the brake system twice at all four wheels and do not see any air bubbles. I do not have any fluid leaking that I can see and the lines all look to be in pretty good shape.

Anyone have any ideas what might cause this?

Thanks for any assistance.

 

[budwich]

did you "bench bleeding" your master cylinder before installing? If not, it takes a lot to get the air out of it. I suspect air some where.

The other possibility is your hoses might be expanding enough to cause the "fade".

 

[trucku]

Take out the master cylinder and bench bleed it. They can get damaged if the pedal is pushed to far when bleeding it in truck. The seals will get torn and your new master cylinder will need replacement. If you think thats the case , buy a rebuild kit.

Sounds like air somewhere in system. bleed them completely again. RR, LR, FR, FL. IF this fails then maybe you should look at your hoses, or that you could have a bad master cylinder.

My truck has ABS and I bleed it with engine off. I have flushed it 2 times so far with no problems, so I think its a bad master or air.


Good Luck

 

[sclime]

Bench Bleeding

Thanks for the quick responses. I did not bench bleed the master when I installed it. I did however bleed the brakes with the motor off. I will pull the master tomorrow night and see if that helps and if necessary can put in a rebuild kit.

Will also check the lines to see if they look like they are expanding. Good suggestion.

I will let you know how it goes.

Thanks,

 

[sclime]

Thanks for the assistance. I was able to bench bleed the master cylinder and then bled the brakes themselves. Had to replace the front right caliper as I could not get the bleed screw to turn and did not want to snap it off.

I now have solid brakes.
Thanks again for the help.

 

[trucku]

Great the hear


Thanks for keeping us posted.