brake fluid leaking when trying to remove calipers

[minghi]

hi all, last weekend i tried replacing the brake pads on my '03 4runner and unbolted the two top bolts on the front driver side caliper and brake fluid started oozing out from between them. immediately i put the bolts back in and tightened it back.

i thought i had to remove all the four bolts to get to the brake pads but a search on the forums showed me that, i can just remove one metal clip and two retaining pins to remove the brake pads, but this didn't work. i could remove all the three clips/pins but the thin metal rod wouldnt budge out even after i compressed the pistons inside using a c-clamp.

please let me know if did anythign wrong. this happened last week and i've been regularly checking the brake fuild level and it remains the same as of now, and if someone had actually removed the four bolts on the calipers and not have brake fluid ooze out. i did change brakes on three cars before - a mazda, an acura and a bmw 740 before, so its not like i'm new to this.

thank you
minghi

 

[greasefingers]

I am confused on this. There are two bolts per caliper for removing it (an upper and lower one). I also remove a bracket that secures the brake line. The only place fluid can escape from is all four piston seals. The brake line is attached by a sliding nut, is that what you loosened?

 

[TechWrench]

I am confused on this. There are two bolts per caliper for removing it (an upper and lower one). I also remove a bracket that secures the brake line. The only place fluid can escape from is all four piston seals. The brake line is attached by a sliding nut, is that what you loosened?

I'm gonna guess that he loosened the bolts that hold the two halves of the caliper together, which is why he had a fluid leak.

 

[TechWrench]

hi all, last weekend i tried replacing the brake pads on my '03 4runner and unbolted the two top bolts on the front driver side caliper and brake fluid started oozing out from between them. immediately i put the bolts back in and tightened it back.

i thought i had to remove all the four bolts to get to the brake pads but a search on the forums showed me that, i can just remove one metal clip and two retaining pins to remove the brake pads, but this didn't work. i could remove all the three clips/pins but the thin metal rod wouldnt budge out even after i compressed the pistons inside using a c-clamp.

please let me know if did anythign wrong. this happened last week and i've been regularly checking the brake fuild level and it remains the same as of now, and if someone had actually removed the four bolts on the calipers and not have brake fluid ooze out. i did change brakes on three cars before - a mazda, an acura and a bmw 740 before, so its not like i'm new to this.

thank you
minghi

What most likely happened was you loosened the bolts that hold the two halves of the caliper together. Unless you are dismantling the caliper for a complete overhaul, you shouldn't need to do this. There are two pins that go thru the two halves of the caliper and hold the pads in place. You have to remove both pins to remove the pads. It is quite common for these pins to rust into place and be difficult to remove. If you have removed the two bolts that mount the caliper to the hub, and the caliper is only attached to the vehicle via the brake line, I would re-attach the caliper to the hub, and then using a rust buster like PB Blaster or WD-40 spray the pins. Then use a pin punch to drive the pins out so the pads can be removed. You may want to get new pins to go along with the new pads. Check the 4 pistons for any signs of fluid leak, and replace them and the seals if there is a leak. It is also possible that one or more of the pistons have become corroded, and will not reseat properly. If so, then it is probably a good idea to replace the entire caliper.

 

[minghi]

thanks a lot guys and apologies for the late reply. too many things happening currently...... anyways, I did try to remove all the four bolts on the back of the caliper and immediately on seeing the fluid leak, I tightened them all up to prevent any further damage. I've been driving the same for about two weeks now constantly checking for any fluid leaks or reservoir level drop and it all looks good. so, i guess, i will get the retaining pins and spray that area with wd40 to loosen the rusted pieces.

also, i have a big c-clamp and its really hard to work with. will a smaller one be easier? hopefully i can order the parts from partznet....

is this what i need?

caliper overhaul kit, 4-runner 03-06 $23.65 $0.00 $17.97
Brakes - Hydraulic system - Rear brakes - caliper overhaul kit

thank you all

 

[jeober]

You also might want to bleed that brake caliper since some air could be present.

Bleeding the brake isn't difficult with two people - one to depress the brake as you open and close the bleed port. There are other ways to bleed the brake lines using air pressure on the fluid reservoir or vacuum on the bleed line, requiring some more equipment.

 

[mmhuffman]

hi all, last weekend i tried replacing the brake pads on my '03 4runner and unbolted the two top bolts on the front driver side caliper and brake fluid started oozing out from between them. immediately i put the bolts back in and tightened it back.

i thought i had to remove all the four bolts to get to the brake pads but a search on the forums showed me that, i can just remove one metal clip and two retaining pins to remove the brake pads, but this didn't work. i could remove all the three clips/pins but the thin metal rod wouldnt budge out even after i compressed the pistons inside using a c-clamp.

please let me know if did anythign wrong. this happened last week and i've been regularly checking the brake fuild level and it remains the same as of now, and if someone had actually removed the four bolts on the calipers and not have brake fluid ooze out. i did change brakes on three cars before - a mazda, an acura and a bmw 740 before, so its not like i'm new to this.

thank you
minghi

I just did the same thing. Replaced the bolts and finished job. Brakes are spongy and need to pump a few times before I get brake action. Pressure does not stay on system. I tightened all four brakes on each side and now I do not see brake fluid leaking, but brakes still do not pressurize without 2-3 pumps. Any thoughts?

 

[TechWrench]

I just did the same thing. Replaced the bolts and finished job. Brakes are spongy and need to pump a few times before I get brake action. Pressure does not stay on system. I tightened all four brakes on each side and now I do not see brake fluid leaking, but brakes still do not pressurize without 2-3 pumps. Any thoughts?

If the seals between the two halfs of the calipers didn't become dislodged, and you are no longer leaking fluid, then you probably need to bleed the entire system. It sounds like you have air in at least one of the calipers, which will cause a spongy pedal. But, if you are still leaking fluid from between the calipers, then it needs to have the seals replaced, or replace the entire caliper.

 

[fourwd1]

Bleed your brake system.
Correct order is
LR
RR
RF
LF
LSPV