I've had the truck only about 2 months but yesterday it developed a pretty scary problem with the brakes. I didn't really find the answer using the search so I hope this is a new one.


In the morning as I was driving I heard a clunk come from the right front wheel area like some metal part breaking or falling off. I did not see anything in the rear veiw mirror and the truck was fine so I went on to work, about 25 miles.

After work I came home and as I got almost home I noticed that it felt like the right front caliper was sticking and the truck was pulling to the right. I pulled over in a gas station to look at and really couldn't see anything much. I checked the fluid and it seemed full but pretty dirty so I decided to go on home and park it and change the pads, fluid etc. on the weekend. It was really sticking but I only had to go about 2 more miles so I went on.

As I got home the pedal lost almost all pressure and when it got within 1" of the floor the wheels would lock up on the rear! Pretty scary but since it's a stick I got it home.

I have to admit, I've never seen anything like this on any vehicle (I'll also confess that I consider a 1992 to a "new" car, most of the cars I own are 25-40 years old and I do all the work on them). Also, I really don't have any sort of experience with computer controlled systems in cars.

I am suspecting something like one of the pads fell out and the piston fully extended letting air in or something like the fluid boiled but I am not familiar with this truck at all and don't even have a manual for it yet. Any suggestions?

Thanks for any help you can provide!

 

i dont think the pad woulda fallen out. have you pulled the wheel off to inspect? if its been sitting that long the pads were probably not good and you are pry running metal on metal. i would replace the pads and bleed out as much of the old fluid as you can.

 

I won't be able to get it off until tomorrow and it's got some alloy wheels on it that I can't really get a good look through. Of what I could see, everything looks OK and nothing is leaking or out of place.

 

they might just need to be bled good pry air in the system but i still dont know what that clunk could be lol when you get the wheels off post some pics

 

The brake fluid is pretty grungy so I'll be taking all of it out and replacing it. I'll probably end up doing a brake job if the pads are worn out (which I suspect they are if the fluid looks like that). The clunk was really weird. I inspected all the suspension points and they look fine so I'm hoping to find something when I get it apart (nothing worse than not finding anything wrong when you know there's something going on).

 

so the pads have NOT been changed yet?

i'm going to say it might be a pinched line in the front, which would cause the lack of braking in the front, and why your rear are locking up... could also be your proportioning valve... could have a seized caliper... i don't think a pad fell off though, they are made so that doesn't happen...

 

Falling off parts means brake pads!!!! I Bonded pads fall apart from overheating. If the caliper is bad then the inner pad should be missing some pieces. You may need new calipers and rotors and pads and the brake line hose. Time to go from end to end and look at the brake line for heavy rust. I got about 15 year on my Grand Marquis before the line near the driver side rear wheel rusted through.

 

could be the rubber lines on the front after a while they get a tare in the inner wall of the line that restricts the fluid flow had it happen a few months ago on my wifes old mimi bus

 

if the caliper is bad the inner pad should be missing pieces? why would he need brake lines if it was working just fine 2 days ago if the lines were rusted out, the level would most likely (95% chance) be low due to seepage and/or leakage

 

they dont leak thats what im getting @ the rubber like gets a rip in the inner wall and it makes a flap and stops the flow of fluid which keeps the piston applied and after the vehicle sits for a while the fluid returns to the reservoir

 

and the rubber line is not a solid rubber tube its made of multiple layers

 

yeah, i understand what you're saying Dale...

 

The heat from the pads would boil the fluid and fatigue the rubber lining of the hose, they would act like balloons and expand under pressure. If they are original then they are 18 years old, that a good reason to replace them.

 

yep u got it

 

All good advice guys. I plan on tearing it all apart starting tomorrow. I notice the one person suggesting that the brake lines are rusted out is from Chicago. This truck spent it's whole life in NC and GA where the chronic "northern rust" isn't that common. I've never seen a rusted out brake line before and I've had over 50 cars (what can I say, I like cars!). There probably is some rust inside the lines as brake fluid is all brown but they seemed to be decent.

I'll let you know what I find.

 

do a full flush of the brake system, get all that brown crap out

 

Well, in the end I took it apart and the caliper that was sticking had a cracked boot and the plastic piston looked heat degraded so I replaced it. Other side was looking good as were the hoses so I left that stuff alone. I was amazed at how similar these were to a Fiat with the retaining blocks so it was really easy for me to work on.

After about two hours and flushing all the cruddy brown fluid out all is well. I still have no idea what made the clunking noise and can't find and damaged parts or places where something looks to be missing. Maybe I did hit something in the road.

 

clunk could have been your caliper sticking and unsticking...