i have a caliper problem?

[sloweighty]

all four of my calipers are sticking and the pads on each sides have the same amount of life, the wired thing about the calipers is that if i drive the car and use the brake more than five times then it will start to stick and heat up real fast and when you need to stop at a stop sign all you have to do is just let go of the gas and then it will start to slow down itself. When the calipers are stick the brake pedal will get real stiff. If i just let it sit for just a couple of hours then it will not stick anymore. So if i am right, my calipers are needed to be rebuild or up grade correct. If anyone can help please help?

[nightsauce]

DUDE!!!! SAME THING HAPPENED TO ME LAST NIGHT......people are telling me i need new calipers. My piston is stuck in the braking position. I'm just going to get some new calipers/rotors tomorrow.

[IanS]

all four of my calipers are sticking and the pads on each sides have the same amount of life, the wired thing about the calipers is that if i drive the car and use the brake more than five times then it will start to stick and heat up real fast and when you need to stop at a stop sign all you have to do is just let go of the gas and then it will start to slow down itself. When the calipers are stick the brake pedal will get real stiff. If i just let it sit for just a couple of hours then it will not stick anymore. So if i am right, my calipers are needed to be rebuild or up grade correct. If anyone can help please help?

Its most likely not your calipers. You have collapsed brake hoses. The hoses have become blocked, by pushing on the pedal you can force fluid pressure past the blockage, but it doesn't not have enough energy to return, this in turn keeps the piston extended.

The best way to tell, remove the bleeder screw from the calipers, if fluid flows easily from the hole, you need new calipers, if the only way to get fluid out is to push the pedal, then you have blocked lines.

If it were me, I would look at this as a reason to get braided steel lines, and Q45 brakes.

Just replace everything and bleed the system, this way you wont risk it happening in the near future.

[sloweighty]

well i bled every side and the brake fluid comes out fine and i do use ATE Blue so i guess i will be up grading.

[IanS]

well i bled every side and the brake fluid comes out fine and i do use ATE Blue so i guess i will be up grading.

Normally a siezed caliper will not retract, even if let sit for a while. I would put my money on collapsed lines. Did you try gravity bleeding?

[sloweighty]

so do i just change the rubber brake lines or do i have to replace the whole brake line and how do i do a gravity bleed

[IanS]

Its the rubber hose part that collapses.

To gravity bleed, just open the resivoir cap, and fill it with fluid. Then open all the bleeder screws at once. Allow fluid to bleed though the system slowly, if any of the wheels flow significantly less fluid, then they most likely have blocked lines.

[sloweighty]

ok i will try that and if it doesn't work then i will go to the junk and pick up some for just right now until i get money for some ss brake lines but can you give me a link where i can learn more about this or can you tell me more on how this could happen and how could the brake line collapsed. Sorry for the Newb questions

[ryan15]

I am interested in hearing this too, not calling BS, just want to hear your explanation.

Ryan

[IanS]

Rubber brake line collapse is actually a very common problem in older cars.

The main cause of brake line collapse is degradation of the rubber itself caused by poor corrosion protection in the brake fluid. This loss of corrosion protection is also what destroys the metal hard lines, basically causing them to rust from the inside out.

Most people don't realized it, but brake fluid, like motor oil is something that needs to be changed on a regular basis. Brake fluid is very hydroscopic, it absorbs water from the air at a high rate. Once the fluid has absorbed enough water its properties change.

As pistons within the braking system move, they scrape off minute amounts of copper which is also collected in the brake fluid, this copper compounds the contamination of the brake system.

On average, I see 1 or 2 collapsed brake hoses at work each month.

I personally flush the brake fluid on all my vehicles on a yearly basis. I consider it cheap insurance.

[sebazztard]

another thing to look at would be the sliders on the caliper brackets. they get rusty and wont allow movement of the caliper itself. take it apart and see whats going on, they may just be seized. happened to me, thought id pass it on. chances on all 4 arent that great, but its worth a check. id check out the above suggestion too. gl.

[sloweighty]

so if i was to replace my brake lines then i should be good then right, and one more question, is it possible for this to happen on all four sides at once?

[IanS]

so if i was to replace my brake lines then i should be good then right, and one more question, is it possible for this to happen on all four sides at once?

It would be one hell of a coincidence. If its happening to all four corners simultaneously, I would start looking at your master cylinder or proportioning valve.

[sloweighty]

proportioning valve.

where is that located at

[IanS]

where is that located at

Not sure on the S13, try checking the FSM.

[sloweighty]

i dont remember seeing one and does every car have this because on my s13 the master cylinder has only four brake lines going to it and then they go there seperate ways.

[nightsauce]

i'm def learning a lot. the same sorta thing is happening to me only my rear passanger brake, looks like the calipers just rusted but the piston is not going in. I had to screw it in and force it back with pliers. :[

[sloweighty]

does anyone knows if s13 have a proportioning valve

[WI_240sx]

yes... most cars do.. more psi to the front, less to the back, very important valve.. the valve that S13 dont have is the residual psi valve, which is used on vehicles with a front rotor, rear drum brake assembly..s13's have all around disc brakes.. shoes have a further distance to travel than pads do, so they keep a small amount of pressure in the drum line to equal the distance traveled by the pads/ shoes...

you probably have a clogged line.. like ian said, debri from the brake system itself can cause blockage, brake fluid is an alcohol based liquid, which is highly corrosive, the reason they use it is because the piston seal and dust boot are made of rubber.. water cant be used because of its freezing point, and oil is a no go because it expands rubber, which would lock up the brakes.. blockage is most likely the cause if you have a stiff pedal.. motor vac makes a flushing system for brakes.. replace parts as nessisary..

[safin]

^ oh damn thanks, you just answered a lot of questions

im swapping the SR from the hatch to a 510, and while cleaning the 510 noticed that the brake system (brake lines and such) looks terrible plus it had an 'extra' valve i knew it had something to do with the datsun having drum brakes in the rear.

i am swapping all of my brake lines, hoses, valve and master cylinder from the 240......... since we are in the topic of brake lines and suchis there like some sort of tool to bend the brake lines? just using my hands would probably bend them irregularly

to the OP, upgrade to steel braided lines...........

thanks!!

[crackler]

Some of this stuff is covered on StopTech's website,.http://www.stoptech.com/tech_i...shtml

Brake Fluid 1Ahttp://www.stoptech.com/tech_i...shtml

Stainless Steel Brake line Q&Ahttp://www.stoptech.com/tech_i...shtml

Brake Proportioning Valves: The True Story of a Misunderstood, Misused and Misnamed Brake System Componenthttp://www.stoptech.com/tech_i...shtml

Hard brake lines at homehttp://www.bikernet.com/events...D=328http://w ... /t....html

Tubing bendershttp://www.google.com/products...title

Sorry I don't have much help for the OP. I would guess something in the M/C if it is in fact all four corners having the same issue.

[WI_240sx]

^ oh damn thanks, you just answered a lot of questions

im swapping the SR from the hatch to a 510, and while cleaning the 510 noticed that the brake system (brake lines and such) looks terrible plus it had an 'extra' valve i knew it had something to do with the datsun having drum brakes in the rear.

i am swapping all of my brake lines, hoses, valve and master cylinder from the 240......... since we are in the topic of brake lines and suchis there like some sort of tool to bend the brake lines? just using my hands would probably bend them irregularly

to the OP, upgrade to steel braided lines...........

thanks!!

yeah, you need a special tool to bend brake lines.. it looks like a tool that you would use to measure an angle... thats because when you bend a brake line you might have to bend it to a cetain angle to fit the car chassis.. its hard to explain what it looks like... just go to a napa or autozone and see if they have it...

[94_240sx]

Proportioning valve is attached to the clutch master sylinder on s13. I was going to suggest taking out the pistons and inspect them, but all 4 corners are doing it, so it should be something else. Lines get separated from master cylinder, so it has to be one central location that control all 4 calipers.

Let me ask you this. I've been wondering about this. You press the brake pedal and pistons come out, right? What happens after you let go of the pedal? Do pistons retract or stay there? You know there's a vacuum line attached to the booster. Does that line retract the pistons? If pistons stay where they are, rotors will touch the pads slightly no matter what.

[sloweighty]

ok i have fix the problem, it was because of the proportioning valve on the master brake cylinder thats why it looks so funny and i replace that and all of my calipers are working fine now..............yay

[WI_240sx]

Proportioning valve is attached to the clutch master sylinder on s13. I was going to suggest taking out the pistons and inspect them, but all 4 corners are doing it, so it should be something else. Lines get separated from master cylinder, so it has to be one central location that control all 4 calipers.

Let me ask you this. I've been wondering about this. You press the brake pedal and pistons come out, right? What happens after you let go of the pedal? Do pistons retract or stay there? You know there's a vacuum line attached to the booster. Does that line retract the pistons? If pistons stay where they are, rotors will touch the pads slightly no matter what.

when you press down the brake pedal, you move 2 seperate pistons inside the master cylinder (1 piston for front brakes, 1 for the rear). in each caliper there are 3 major parts to the caliper. the piston, the dust boot, and the piston seal.. when you push on the brakes, the pistons move out, which causes the piston seal to twist, kind of like twirling a rubber band, when you let off the brake, the piston seal naturally wants to untwist its self, causing the pads to release the brake rotor..