Does your front end lock up in the rain?

[Mike 97]

I have been having a problem with my front end locking up. It does it from just about any speed over 10mph - most noticeable when going downhill. I put Toyo open country at tires on last year, new brakes all the way around last weekend. Does anybody else have this problem? Every time it rains now when I am on the highway my heart goes into my throat when traffic slows down quick. Could it be the tires? I have Raybestos Superstop shoes shoes and Akebono pads pads

Any ideas?

Thanx

oh yea - it doesn't have four wheel abs

 

[2001ExpSport]

Do they lock up when you just touch em or when you get on em hard?

 

[Doug]

If you dont have 4wabs you probably only have rear wheel abs. the system is working correctly but there is nothing to keep the front tires from locking up except for driver input.

 

[2001ExpSport]

Originally posted by Mike 97
oh yea - it doesn't have four wheel abs

 

[Mike 97]

The front end locks up - downhill - with hardly any pressure.

 

[GaSouthern1]

It is because rust forms on the discs if they have been sitting in the rain for even a short amount of time. Once the rust forms the pads grip on it very easily and they lock up, my Cherokee did this as well.

 

[Alec]

Does pumping help at all?

 

[Mike 97]

Pumping may help - I only find myself skidding on steep downhills. If I am quick enough I can back off to get the wheels to unlock and reapply and stop in time to not slide through the intersection. The thing that worries me is an emergency - I may not have enough time to ease into the brakes to slow down. Should I be looking at better tires? I think I am going to take it in to a shop and let them look at it. Any suggestions? Should I avoid brake shops like midas? Do they do complete systems or is it mostly pad / shoe work?

 

[Majisto]

Hmm...do you have drum rears or discs? The only thing I can say is make use of your "2" and "1" selectors on the transmission. Engine braking can really help going down hills.

 

[Alec]

It's normal for a non-ABS truck to skid on steep downhills. Weight transfer really promotes wheel lock.

Did this happen before your brake job? If so, what's the difference from before and after? And how bad were the brakes you removed?

 

[Mike 97]

The brakes I removed were wagner thermo-quiet pads. I think these new pads have much more grip. The rears have never locked up on me - yet...

 

[Mike 97]

How much of an effect would air in the lines have? Could I just need to bleed the system?

 

[Alec]

I don't think that would cause quick lockup, but I could be wrong.

 

[Majisto]

Air usually just means your brake pedal will feel soft. It can also cause the brakes to engage slower since there is less line pressure. If the brakes are locking though, the brakes are locking. You put more pressure it ain't going to help anything.

You may need some better tires, or just check the inflation levels.

 

[xxblackxx]

do they feel like they have a tendacy to lock up on dry pavement too?

it could be a bad proportioning valve, sending too much hydraulic pressure to the front.

the HCU could be bad too, but there is a myriad of things that could go wrong and cause something like that. Im too lazy to look it up in the workshop manual too

 

[Alec]

If you do have a proportioning valve I'd send more power to the rear and see what happens.

 

[xxblackxx]

Originally posted by Alec
If you do have a proportioning valve I'd send more power to the rear and see what happens.

a proportioning valve is not adjustable, it is a "hard" component that directs a specified amount of hydraulic pressure to the front/rear circuits, based on the factory settings. It in simple terms, distributes pressures typically 70/30 (most likely on an explorer) more to the front to prevent excessive rear brake applicatioin (which would result in wheel lockup.)

Im not sure if an explorer has it (i really doubt it) but some cars like taurus' and sables have a height sensing proportioning valve that when heavier loads are applied over the rear axle, a pushrod that is mounted against the body (while the valve is mounted on the axle, thus a smaller distance between body and axle would be present) will compress into the valve, allowing more fluid to flow to the rear (based on the theory that more weight in the rear = more traction so more pressure in the rear circuit can be applied without wheel lockup)

Follow?

 

[Majisto]

I didn't know my Taurus had one of those...it probably does. It seems to brake fairly well even though Ford went cheap and put drums in the rear. I need to go bleed those brakes out.

 

[mhn3773]

i do not own an explorer but because of my dads job i have drivin mountys exs from several years i have never had a problem with the tires locking up like that down hill in rain i mean i have had them lock up but only when i wassent p[aying attention then had to stop so i jabbed the breaks but once i let off and got back on they slowed me w.o skidding

 

[Mike 97]

xxblackxx - yes, they used to lock up on dry pavement until I got rid of the firestones.

I am taking it to the dealer - I think it may have somthing to do with the proportioning valve