My 97 'runner has some very undesireable characteristics and I'm unsure where to begin.

Any time I have to brake hard, the front end dives (like nearly bottoms out) and pulls hard to one direction, usually the left. The first couple times I did it, I wasn't expecting it and the wheel actually got yanked out of my hand and nearly caused a wreck. I'm not locking up the wheels in these cases, but this would be like the "someone slamming on the brakes in front of me" or "jackass in a minivan cutting me off" type of stop/slowing.

I'm unsure why it pulls so hard, but that combined with the full front weight transfer nearly makes me lose control, because the back end can "float" as the front digs in.

Any suggestions on where to start? It's a definite safety issue.....

 

rotors, sticky caliper first come to mind.... also alignment can contribute as well....

 

I had similar with my s10, but it clunked too it was loose front end parts or a bad ball joint I can't remember wich but I know it made me switch lanes a few time when I hit the brakes.

 

I will second probably a sticky caliper, check air pressure too. I would also make sure you adjust the rear brakes to be sure they are working good too so you get more even stops when braking hard.
Have you noticed any stearing wheel shake when braking downhills ? usually a sign of warped rotors. went thru 2pairs on mine(96) till I switched to crossdrilled ones.

 

I would say it is diving hard because the rear brakes are out of adjustment.

I'd almost put $100 on one of your calipers being bad and not braking enough. I've had it happen to me a couple times on other vehicles. It does exactly what you described.

So all you have to do is replace the calipers and adjust the rear brakes.

Good Luck

 

First, I would suspect that the left caliper has a problem, maybe brake fluid leak on the pads. That could make them grab. Also if you have grease or oil on the right side pads, they would not grab as much as the left. but I would also have someone check on the proportioning valve. If it is stuck or not working, it could make the front brakes do all the work and this would cause the front end to 'dive' when braking.

 

Good point. I completely forgot about that little thing on these Toyotas.

 

I have this exact same problem. (pulling to the left and nose diving during hard braking)
I am more concerned about the pulling to the left when braking hard than the front end diving down. I know how to fix the nose dive thing and will the next time I get a chance.
I just changed the rotors and pads a couple of weeks ago. Before changing the rotors I did not know if I had this problem because I was so concerned with the vibrations during high speed braking.
I suspected the calipers were not functioning properly so I flushed the brake system (thank you gadget for the motive power bleeder recommendation, it works great). This did not help but I am glad to "clear" fluid in the system. I know I still could have a bad caliper but it was worth a shot. How do you test for a bad caliper?
I will wipe down the rotors with a rag and brake cleaner to rule out grease or brake fluid messing up the rotor pad interaction. If this does not help then I has to be what I orginally suspected, a steering, suspension or alinement problem. I would like to rule out a steering or suspension problem before getting the truck aligned. What test or inspection do yall recomend I perform first to find any steering or suspension problems? Also the person that owned the truck before made it a point to replace only one tire at a time so the truck has four different brand tires all worn to a different level but they all seem to be the same size. Could this be contributing to the problem?

 

Pulling to the left during braking definitely suggests a possible problem with the rotor, caliper, or brake pads.

Excessive front end nose dive is a problem that is commonly associated with worn shocks. That'd be my guess, especially for a '97 if you have more than 75,000 miles on it.

It is a terrible, terrible idea to replace one tire at a time. Absolutely terrible. Tires are best replaced all 4 at the same time, though you can get away with only replacing all the tires on 1 axle. Why? Because as tires wear, they lose circumference. You don't want 1 tire to be slightly smaller than another on the same axle, as they will spin at different rates while driving straight, cause the vehicle to lean to one side putting stress on those components, and even interfere with steering. They should also be the same manufacturer and model of tire, for the same reason (different tread patterns, materials, etc).

Bad juju.

~Bill

 

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Pulling to the left during braking definitely suggests a possible problem with the rotor, caliper, or brake pads.

Excessive front end nose dive is a problem that is commonly associated with worn shocks. That'd be my guess, especially for a '97 if you have more than 75,000 miles on it.

It is a terrible, terrible idea to replace one tire at a time. Absolutely terrible. Tires are best replaced all 4 at the same time, though you can get away with only replacing all the tires on 1 axle. Why? Because as tires wear, they lose circumference. You don't want 1 tire to be slightly smaller than another on the same axle, as they will spin at different rates while driving straight, cause the vehicle to lean to one side putting stress on those components, and even interfere with steering. They should also be the same manufacturer and model of tire, for the same reason (different tread patterns, materials, etc).

Bad juju.

~Bill"

Thanks for the tip. Oxnard, hey thats just down the 101. Actually I have 92 2wd w/ 110k on it. I am definately getting new shocks but do not want to get new tires because mine still have alot of tred on them even though they are all mismatched thanks to the last owner. What about the steering linkage could these componets be contributing to the left pull when braking? How do I test for this? Also how do I test for a bad caliper?

 

having all different tires can severly add to the problem or end up being the casue of the problem... if one has better traction then the other... a pull will result also the size difference too...

 

Thanks new tires it is.

 

I just replaced my shocks again and noticed a big difference in braking. Highly recomend it

 

Yeah, I've partied over on State Street more than once.

Steering linkage can best be tested by inspection: Read here

Though it'd be best if you just took it to a reputable place. I've had good experience with Big Brand Tire in Oxnard, and heard many good things about Big Brand Tire in Ventura. They should be able to take a good look at your linkage and other suspension components and let you know if anything needs replacing.

Unfortunately, suspension work can start running into $$$, and if you're coupling the cost of new tires with that it can really add up. Unfortunately, if you just have suspension work done, the root cause is still there and you'll end up with a suspension problem again. If you replace the tires and have a worn suspension, then the tires will wear out quicker and may give you more suspension problems. A nice little catch-22.

For really good info on testing your calipers, go here

The '97 comment was directed towards denverbikeguy, but if you have a '92 with that much mileage I'd definitely suspect shocks were causing the front end dive.

Hope this helps,

~Bill

 

Thanks for the replies guys! I should also add that the thing handles like crap - i.e. bumps that my g/f's saturn just rolls over like they're nothing, cause a pretty rough ride for the 'runner. It's also not uncommon for it to kick out the back end on a nice big bump, or cause other directional issues. Thinking suspension just needs a big farkin overhaul here.

So ... shock recommendations? I was considering the Bilstiens, I figure they might also raise the ride height by a half inch or so which is good too.

 

Don't go off the deep end with brakes until you have the rears properly adjusted. Both of my 4Runners consistantly need the rears adjusted. A good test is how far you have to pull the parking brake. If it's easy to pull, the rears need to be tightened. Likewise, when they are properly adjusted, there will be more tension on the parking brake.

The diving is more than likely caused by adjustment issues, but also the pulling could be as well. If one rear wheel is tighter than the other, your truck could pull considerably depending on the difference in adjustment.