WTH is wrong with my truck?

[TheFlyKneeGrow]

Grr.

An hour ago I made a run from town up into the mountains. 95% of the journey was on mildy hilly paved roads, with the final stretch being a short climb up a dirt road to a home up on a mountainside.

I've made this trip countless times, and each time I get to the transition of pavement to dirt road I slow down and engage the push-button 4x4, then do the reverse as I'm leaving the dirt for the pavement.

Today, however, my truck developed two new problems just after I disengaged the 4x4...

First, it was suddently wobbling oddly and pulling pretty hard to the left (like a low tire or some sort of suspension problem). I pulled over, looked around, and saw no obvious problems. I got back on the road and a few minutes later it went away. Sort of like the 4x4 was still engaged, yet none of the indicators lit up?

Then, inexplicably (to me at least), suddenly the brake pedal went all mushy and I literally had to press it to the floor to get any stopping power. I pulled over again, looked around underneath the truck, rocked it back and forth, and saw no obvious problem.

I continued my trip back to town, the brakes continued to be totally mushy and still are. Even when pressed to the floor it just barely will stop the thing, and while the majority of the pulling-to-the-right has stopped it still seems off a bit.

Does any of this make any sense? What in the @!%$ is going on here?

Anyone, anyone, Bueller?

Thanks in advance.

Fly

 

[doonze]

What's the fluid level look like for the break fluid? I would bet something went south on your left caliper, kind of engaged it for a bit and leaked out fluid. I bet now your fronts are out and your running just on your rear brakes, that's why the front/rears are seperate parts of the system. This would be my guess.

 

[james t]

1- The 4x4 issue- more than likely it was still in the process of shifting back into 2 wheel drive. No biggie, it will usually pull weird on dry pavement while still in 4x4. If it seems annoying give it a little extra time to shift

2- The brakes- Wild guess but im pretty sure you need to flush and replace the brake fluid. As fluid gets older, it absorbs moisture. Also, the fluid in the calipers and wheel cylinders will cook. It may not be noticable during normal driving and only become an issue on hilly drives when you are on the brakes alot.


To sum up, ignore the weird 4x4 delay and change the brake fluid.

 

[TheFlyKneeGrow]

thanks for the responses.

I'm working now but will check the brake fluid later. There's no apparent leakage, btw.

Regarding the brakes, it seems particularly odd to me that they'd go from 'normal' to complete mush all of a sudden and yet it only needs a fluid change? Is that typical? Should I not be concerned with the sudden nature of the change, something akin to someone flipping a switch? Working fine one sec, almost no brakes the next?

 

[james t]

Well, it technically wasnt "all of the sudden", it was "suddenly after you really used them and added alot of heat".

Thats the problem with old brake fluid thats cooked, degraded, and holding moisture. It may seem fine during around town trips, but once you start stressing the brakes (like driving in hilly areas/using the brakes on the downside of the hill) the fluid heats up and the moisture in the fluid boils. This makes the brakes go to mush quickly. Once the moisture boils it is similar to suddenly getting air in the lines. Park it for several hours, let it all cool back down, and the brakes sortof come back.

Go get a big bottle of brake fluid, and bleed the hell out of them and i bet it works. Cheap to try anyway.

 

[Happy Jack]

I'd pull your front wheels and check your wheel bearings. I had the brake thing happen to me once and thats what it was. Check your lock outs and wheel bearings. May not be it but I check mine every spring before i start my years off roading trips.

 

[TheFlyKneeGrow]

sweet, thanks guys.

 

[TheFlyKneeGrow]

one last question - what synthetic brake fluid do you suggest?

 

[james t]

one last question - what synthetic brake fluid do you suggest?

Whatever's closest to the front of the store. Its all good.

 

[rayford2]

Grr.

An hour ago I made a run from town up into the mountains. 95% of the journey was on mildy hilly paved roads, with the final stretch being a short climb up a dirt road to a home up on a mountainside.

I've made this trip countless times, and each time I get to the transition of pavement to dirt road I slow down and engage the push-button 4x4, then do the reverse as I'm leaving the dirt for the pavement.

Today, however, my truck developed two new problems just after I disengaged the 4x4...

First, it was suddently wobbling oddly and pulling pretty hard to the left (like a low tire or some sort of suspension problem). I pulled over, looked around, and saw no obvious problems. I got back on the road and a few minutes later it went away. Sort of like the 4x4 was still engaged, yet none of the indicators lit up?

Then, inexplicably (to me at least), suddenly the brake pedal went all mushy and I literally had to press it to the floor to get any stopping power. I pulled over again, looked around underneath the truck, rocked it back and forth, and saw no obvious problem.

I continued my trip back to town, the brakes continued to be totally mushy and still are. Even when pressed to the floor it just barely will stop the thing, and while the majority of the pulling-to-the-right has stopped it still seems off a bit.

Does any of this make any sense? What in the @!%$ is going on here?

Anyone, anyone, Bueller?

Thanks in advance.

Fly

I had the same problem 2 years ago on my '94XLT. Front U-joint was bad. Replace both of them while you're at it, and get the ones with the grease fittings on them so you can take better care of them.