front calibers sticking ?

[steve-a]

98 4Runner 4x4, bought used with 84k on it. 88k front end was pulsating bad when brakes where applied. Turned rotors, pads looked new so i did not change pads. 92k pulsating when brakes applied. Turned rotors and replaced pads. 98k front end pulsating when brakes applied. At this time I thought front calibers are sticking. Gets 17-18mpg, does not pull to right or the left when appling brakes. Nothing to make me think that the calibers were sticking. So replaced rotors with high performance rotors and trd pads. One thing I have noticed thoughout this entire process is when I let it sit for 48 hrs and then start it and try to take off, its as if the front end is locked up and i haft to apply a lot of gas to get it to move. Once I get it to move everything seems fine, but this sticking issue seems to be getting more freequent. I know the right thing to do is to get someone to look at it, but has anyone herd of this. I was looking for some info so the brake shop wont take me for a ride.

[KimMG]

Did you replace the flex lines? They deteriorate internally causing blockages that act like one-way valves.

[steve-a]

I have heard of people replacing flex lines, but mostly on older automobiles. I fell like I could replace the lines myself, but is there any way to know for sure this is the problem. And can I pick them up at a local auto parts store. My 4Runner has been sitting for 4 days now so tomorrow I am going to jack up the front end and see if the front wheels will turn freely. Any other advice would be greatly appericated.

[KimMG]

Deteriorated flex lines on vehicles that are older than five years is common. Not too difficult to replace if you have flex line wrenches and know how to bleed the brakes. Flex lines are available at auto parts stores, although they maybe a special order item. You also need to make sure that the calipers are not sticking. Sticking calipers caused by either bad flex lines or bad calipers will generate excessive heat causing the rotors to warp.

[steve-a]

On thursday the 22nd I performed these test. Jacked up front end and spun both tires by hand. They turned very easly so I started it, let it warm up and then spun both tires by hand. Same result, they turned easly. I let the front end down, got in and depressed the brake to put it in drive. Released the brake and it may have moved 1 inch then locked up. I had to depress the gas pedal quite a bit to get it to move. Then when I went to stop again and depressed the brake it stopped very hard, like it was locking up. Someone suggested to me this could be a transmission problem. Front wheels seem to be spinning fine, but something locks up when I put it in drive and goes away after the frist couple of stops.

[fourwd1]

You've done all that work and haven't checked to see if the calipers are frozen or sticking ?
You need to check the basics instead of blindly replacing things. And you've had the calipers off to replace that stuff.

[falconman26]

Check the Hand Brake for play. I have a 97 4Runner, V6 Stick Shift. If I leave it standing for more than a day, the rear wheels used to jam, same problem that you described in your post. It seems that once I pull the Hand brake, it won't release fully till I drive for a while. I still have to fix it, for now, I just go under the 4Runner and push back the Hand Brake wire back in to release it.

[RdRunnr]

HI,
Did you try a careful bleeding of the brakes? It doesn't take much air in the system to cause the brakes to drag. Fluid gets warm, air expands...becomes a vicious cycle (and the brakes will seem normal when cold). The initial sticking (or very touchy pedal) after sitting a night may be caused by a very thin layer of rust the naturally forms on the rotor. Usually one or two stops cleans the rotors and all is well. Some brake pads(semi-metalic)seem immune from this problem while others are very prone.

[steve-a]

Sorry that i'm taking so long to reply. In my early post I did not mention that my 4Runner is my second car and spends most of its time in the grarage while I drive my 89 toyota truck. For the past two weeks I've been driving my 4Runner and my brakes have been working perfect. I've even checked my gas mileage again and i am averageing 20.5 mpg. Don't understand that but i have switched from 10w30 to 5w30 and with the new rotors my brakes don't pulsate anymore. Seems like it only acts up when I let it sit and don't drive it for a while. If anything changes I will post again, if anyone else has a coment please post.