Brake Issues!

[91explo]

I was up the hill playin around for the day and as I was on my way down my brakes pretty much gave out on me. While I was braking my pedal went to the floor and i was barly able to stop. I think the only thing that was slowin me down was my rear drums. So i managed to get down using my gears.I was testing my brakes on the way down and somtimes they felt fine...:S Im thinking mabey they got to hot? or mabey there is air in the lines? After work today I will try them out again but Im worried it may happen when im drivin on the highway. any suggestions to what it is?

 

[Exploderpilot]

not sure what it is, but i would definitely go over the whole system with a fine toothed comb. take the calipers apart, flush and bleed the fluid side, check the drums and plates in the rear.

 

[91explo]

Ya i'm thinkin there mabey a leak...but the fluid level hasnt changed...

 

[manaen]

how steep was this hill?

is it possble the hill was steep enough to slosh the brake fluid forward that it couldnt prime the master cylinder?

I've never heard of that happening, but I'm just thinking outside the box here..

 

[mikeinri]

I doubt you just overheated the brakes running down the hill. Normally if that happens, the pedal pressure doesn't change, but your stopping distance increases.

Sounds like you may have a small leak. One way to test this is to park in a driveway, etc. (with no existing fluid puddles) with the engine turned off. Pump the brakes and hold the pedal, putting as much pressure on the pedal as you can.

If a wheel cylinder is on its way out, this will usually blow it and give you the answer.

If you have a pinhole leak somewhere else, doing this test several times should pump out enough fluid so that when you look under the truck, you can see fluid and trace it back to the source.

If you rule out a leak, you may have air in the system as mentioned, or a bad booster or master.

Whatever you do, don't drive the truck on the highway (or anywhere else for that matter) until you get this fixed.

Hope this helps, let us know how it turns out.

Mike

 

[91explo]

WOW i didnt expect that to be it!!!!

i finally had time to check out why i lost my brakes and went over everything....checked the master cylinder...checked the lines..no leaks. i jacked it up and took the tires off. As i went to loosin the lugs on the drivers side i noticed the my tire had ALOT of play in it before i even started loosing the lugs!! once i got the tire off and did some inspecting i noticed that the iner brake pad was GONE!! litterly...like it fell out somehow! I do need the change the pads but they wernt metal on metal. the piston is actually acting as a brake pad on the inside...ouch. i hope ican save the callipers. im thinkin somehow somthing got up there and pushed the pad out? i hope everything works out once i put new pads in. thanks for all your suggestions guys...explorerforum thumbs up

 

[glfredrick]

Sounds like you heated a pad to the point where it lost its bonding with the metal backing plate.

That can happen fairly easily if the pads are worn thin. I've changed out several sets like that of late...

Best bet is to replace the rotors and pads. If you have been metal on metal, your rotors will be too far gone to turn.

I'd also change the brake fluid while you're at it -- as you bleed the system, start with the wheel farthest from the master cylinder -- either pull (with a vacuum pump) or do the old pump it up, hold it, and loosen the bleeder screw routine until the fluid runs out clear and new. Make sure someone sits at the master cylinder and keeps it topped off with fluid as you do this! Once you get that wheel clear, move to the other rear, do the same, then the passenger side front, then the driver's side front.

Brake fluid collects moisture from the air, and eventually gets saturated with water, which does two things: First it rusts the brake lines from the inside, and second it boils faster when it gets used hard. Boiling brake fluid means very spongy brakes. It is also hard on the braking system seals.

 

[91explo]

Sounds like you heated a pad to the point where it lost its bonding with the metal backing plate.

That can happen fairly easily if the pads are worn thin. I've changed out several sets like that of late...

Best bet is to replace the rotors and pads. If you have been metal on metal, your rotors will be too far gone to turn.

I'd also change the brake fluid while you're at it -- as you bleed the system, start with the wheel farthest from the master cylinder -- either pull (with a vacuum pump) or do the old pump it up, hold it, and loosen the bleeder screw routine until the fluid runs out clear and new. Make sure someone sits at the master cylinder and keeps it topped off with fluid as you do this! Once you get that wheel clear, move to the other rear, do the same, then the passenger side front, then the driver's side front.

Brake fluid collects moisture from the air, and eventually gets saturated with water, which does two things: First it rusts the brake lines from the inside, and second it boils faster when it gets used hard. Boiling brake fluid means very spongy brakes. It is also hard on the braking system seals.

Ya i will change the fluid,and the rotors are in rough shape...mostly the inside on both. I guess this is what can happen if you dont go over everything after buying a used rig before you start drivin it. I mean you should check it out before buyin it to but hey i got it for 600 bucks (canadian) shes got 314,000kms runni strong and the lifters make a little ticking every so often but hey i heard of the 4.0s running a long time on tickin lifters. anyways im gonna start doin the brakes next week when i have some extra money, mabey ill do the calipers to just because i drove 20km on the one piston acting as a brake pad....ouch.