Caliper Rebuild Thoughts/Observations
12-30-2015, 07:32 PM
#1
Three Wheelin'
Thread Starter
Caliper Rebuild Thoughts/Observations
There are a few write-ups already on the subject so I will try to address some of the points that were not obliviously mentioned.
Parts
The parts are pretty simple. 10mm wrench, caliper allen socket, air-compressor, small screwdriver, old pads, gloves or something soft when removing pistons, channel wrench (pry out pistons). I used the Centric kit parts (143.37025 front, 143.37009 rear), Centric Hydraulic brake assembly fluid
Calipers on Rotor
I would highly recommend bleeding the brakes before taking the calipers off the hydraulic line. I did not and it causes a big mess with the brake fluid. Also, when you actually get the caliper off the fluid can get all over the place.
For a while I did use fluid stoppers. They worked great and a good job of sealing the line so no fluid comes out of the end of the hydraulic line.
4) Front brakes to the hydraulic line (10mm) wrench screw to loosen. But you are not done. You need to remove the line which requires a hard pull away from the caliper to get the ball end out of the caliper. I did not know this and kept turning the screw. There was little resistance, but since I did not hear about this I turned for a little while. I eventually learned about the ball at the end and was able to pull out the line. In the process I either damaged the line (about a $50 part) or even worse the threads inside the hydraulic part of the caliper. I will find out more then I get the new part. This was very frustrating and I learned not to repeat this for the other 3 calipers. Note, the rear calipers have an additional 10mm screw you need to remove before you can take the caliper off. So, the hydraulic line plus another screw the holds the assembly.
In general, two-way line hydraulic port and to brake line is a pain and needs to be in the perfect position to install to both places and takes some force to line up correctly. It might be easier to remove it from the brake line to remove the tension so you can easily screw it into the caliper, and do the line part second. For one of the lines it took me at least 20 minutes to get both ends connected. The struggle is getting the first parts of the thread to catch into the caliper while not pushing in the ball part of the line.
Brake Lines
I did put in new Stainless Steel brake lines. Note the nut by the caliper is 10mm and the one near the chassis line is 11mm. The front lines were no issue and you have plenty of access even with the caliper on. However, I still have NOT been able to remove the nut/line by the caliper in the rear. The 11mm line by chassis is easy to take off, but the ones near the caliper don't seem to budge even with penetrating oil!
Pistons
As others of mentioned use an air compressor to get the pistons out of the calipers. You need a good rubber tip that goes into the hydraulic port.
This is really trial and error. Ideally you will have several large rubber clamps because the likelihood of all pistons coming out on the first attempt is low. Note, say 4 come out the first time you will need to put them back or totally seal the bores to attempt to remove the other 2 pistons. I used a combination of old pads, and wood blocks and it was a total pain in the ***. This is where the channel lock pliers come in handy. Just put something soft covering the piston before you try to put it out. What worked best for me was to rock the piston to get it out. Note, if all ports are not sealed nothing will happen. Say you only have 1 port open nothing will happen to help remove the other 5.
Watch your fingers because it really stings when they pop-out via an air compressor. This is where something soft like a workers glove or towel helps and/or block of wood. You want the pistons to some partially out in cause one did not come out.
Yellow Pucks
I had a few half broken pucks embedded in the pistons and they would not come out with any force. You need to be careful not to stretch the piston when trying to remove a broken puck. I was lucky to have replacement pucks
Based on a rennlister’s advise - I heated the piston/puck in the oven at 400 degrees for about 8 mins for the largest piston and it came right off with little effort. For the smaller piston heated for about 5 mins. Depending on the condition of the puck some were able to "snap" in. For one or two I used crazy glue for the install. Remember the pads & force will keep them in place.
Clean Caliper
This is a royal pain. I used simple green with a tooth brush and it removed the surface stuff. I guess you can use something a little more aggressive for better results. It is good remove surface stuff because as you are handling the caliper to put in the seals, boot and pistons your hands will be dirty.
Putting the caliper pistons, boots, and seals
To change the old seal you will need a very small screwdriver or prying tip to remove the seal. It is pretty easy to get it out. The OEM seal actually has marks on it. By the way, all the OEM seals looked pretty good as an observation. Use brake assembly fluid for seals and pistons. You put the seal back in by hand -- feel your way. For a few pistons I thought the seal was in correctly, but the piston did not go in - So I forced it in --- wrong! This means repeating the air compressor again! So, if the piston is difficult to go in stop and take out the seal and put it in correctly. The piston should go in with little effort.
Before I put the piston in the caliper I put on the dust boot on the piston. It requires a little stretching of the boot based on the bottom of the piston. I did not want to put the boot on after the piston was fully in the caliper because I felt the dust boot would get caught up. Once the piston was around 80-90% in the boot would be close to the yellow pucks. Now I could guide it on to the ring while it is around the piston. Once the piston was fully in I was able to secure the dust boot by pushing on opposite sides, e.g. top and bottom to get it to seal. This process worked well.
The only really tricky thing is not to force the piston and make sure the seal is in correctly. It may look like it is in correctly, but the piston will tell you if it is not.
Finished Caliper
I put in the pads and bracket and put it on the rotor. Basically the whole completed caliper on the rotor.
Key here is getting the line back into the same shape before you pulled it out of the caliper. Again, a good practice is to first disconnect the brake line so it is easy to screw the line into the caliper. You have more flexibility with the brake line than you do with the side that goes into the caliper.
In summary, this requires a lot of patience. I read all the posts which were very helpful, but it took much more time than I expected because of the various problems I encountered such as broken pucks, hydraulic brake line issues, etc. I would rate my skills towards the novice level, e.g. rotors, pads, brake fluid and oil change. For an experienced person this should not be too difficult.
I just hope I did not screw up the first front caliper and/or I will be able to re-thread if necessary. The brakes are so over engineered even with all my track years on the car the brakes were fine. Hopefully, I will not have any leaks when I put the fluid back in, and will figure out the other issues.
Best of Luck!
Parts
The parts are pretty simple. 10mm wrench, caliper allen socket, air-compressor, small screwdriver, old pads, gloves or something soft when removing pistons, channel wrench (pry out pistons). I used the Centric kit parts (143.37025 front, 143.37009 rear), Centric Hydraulic brake assembly fluid
Calipers on Rotor
I would highly recommend bleeding the brakes before taking the calipers off the hydraulic line. I did not and it causes a big mess with the brake fluid. Also, when you actually get the caliper off the fluid can get all over the place.
For a while I did use fluid stoppers. They worked great and a good job of sealing the line so no fluid comes out of the end of the hydraulic line.
4) Front brakes to the hydraulic line (10mm) wrench screw to loosen. But you are not done. You need to remove the line which requires a hard pull away from the caliper to get the ball end out of the caliper. I did not know this and kept turning the screw. There was little resistance, but since I did not hear about this I turned for a little while. I eventually learned about the ball at the end and was able to pull out the line. In the process I either damaged the line (about a $50 part) or even worse the threads inside the hydraulic part of the caliper. I will find out more then I get the new part. This was very frustrating and I learned not to repeat this for the other 3 calipers. Note, the rear calipers have an additional 10mm screw you need to remove before you can take the caliper off. So, the hydraulic line plus another screw the holds the assembly.
In general, two-way line hydraulic port and to brake line is a pain and needs to be in the perfect position to install to both places and takes some force to line up correctly. It might be easier to remove it from the brake line to remove the tension so you can easily screw it into the caliper, and do the line part second. For one of the lines it took me at least 20 minutes to get both ends connected. The struggle is getting the first parts of the thread to catch into the caliper while not pushing in the ball part of the line.
Brake Lines
I did put in new Stainless Steel brake lines. Note the nut by the caliper is 10mm and the one near the chassis line is 11mm. The front lines were no issue and you have plenty of access even with the caliper on. However, I still have NOT been able to remove the nut/line by the caliper in the rear. The 11mm line by chassis is easy to take off, but the ones near the caliper don't seem to budge even with penetrating oil!
Pistons
As others of mentioned use an air compressor to get the pistons out of the calipers. You need a good rubber tip that goes into the hydraulic port.
This is really trial and error. Ideally you will have several large rubber clamps because the likelihood of all pistons coming out on the first attempt is low. Note, say 4 come out the first time you will need to put them back or totally seal the bores to attempt to remove the other 2 pistons. I used a combination of old pads, and wood blocks and it was a total pain in the ***. This is where the channel lock pliers come in handy. Just put something soft covering the piston before you try to put it out. What worked best for me was to rock the piston to get it out. Note, if all ports are not sealed nothing will happen. Say you only have 1 port open nothing will happen to help remove the other 5.
Watch your fingers because it really stings when they pop-out via an air compressor. This is where something soft like a workers glove or towel helps and/or block of wood. You want the pistons to some partially out in cause one did not come out.
Yellow Pucks
I had a few half broken pucks embedded in the pistons and they would not come out with any force. You need to be careful not to stretch the piston when trying to remove a broken puck. I was lucky to have replacement pucks
Based on a rennlister’s advise - I heated the piston/puck in the oven at 400 degrees for about 8 mins for the largest piston and it came right off with little effort. For the smaller piston heated for about 5 mins. Depending on the condition of the puck some were able to "snap" in. For one or two I used crazy glue for the install. Remember the pads & force will keep them in place.
Clean Caliper
This is a royal pain. I used simple green with a tooth brush and it removed the surface stuff. I guess you can use something a little more aggressive for better results. It is good remove surface stuff because as you are handling the caliper to put in the seals, boot and pistons your hands will be dirty.
Putting the caliper pistons, boots, and seals
To change the old seal you will need a very small screwdriver or prying tip to remove the seal. It is pretty easy to get it out. The OEM seal actually has marks on it. By the way, all the OEM seals looked pretty good as an observation. Use brake assembly fluid for seals and pistons. You put the seal back in by hand -- feel your way. For a few pistons I thought the seal was in correctly, but the piston did not go in - So I forced it in --- wrong! This means repeating the air compressor again! So, if the piston is difficult to go in stop and take out the seal and put it in correctly. The piston should go in with little effort.
Before I put the piston in the caliper I put on the dust boot on the piston. It requires a little stretching of the boot based on the bottom of the piston. I did not want to put the boot on after the piston was fully in the caliper because I felt the dust boot would get caught up. Once the piston was around 80-90% in the boot would be close to the yellow pucks. Now I could guide it on to the ring while it is around the piston. Once the piston was fully in I was able to secure the dust boot by pushing on opposite sides, e.g. top and bottom to get it to seal. This process worked well.
The only really tricky thing is not to force the piston and make sure the seal is in correctly. It may look like it is in correctly, but the piston will tell you if it is not.
Finished Caliper
I put in the pads and bracket and put it on the rotor. Basically the whole completed caliper on the rotor.
Key here is getting the line back into the same shape before you pulled it out of the caliper. Again, a good practice is to first disconnect the brake line so it is easy to screw the line into the caliper. You have more flexibility with the brake line than you do with the side that goes into the caliper.
In summary, this requires a lot of patience. I read all the posts which were very helpful, but it took much more time than I expected because of the various problems I encountered such as broken pucks, hydraulic brake line issues, etc. I would rate my skills towards the novice level, e.g. rotors, pads, brake fluid and oil change. For an experienced person this should not be too difficult.
I just hope I did not screw up the first front caliper and/or I will be able to re-thread if necessary. The brakes are so over engineered even with all my track years on the car the brakes were fine. Hopefully, I will not have any leaks when I put the fluid back in, and will figure out the other issues.
Best of Luck!
12-30-2015, 10:51 PM
#2
Rennlist Member
Nice review! It is a messy job, but wise maintenance for our 12-13 year old track machines.
01-02-2016, 03:38 PM
#3
great write up. It convinced me to call John at Haworth Racing. Need to just work out my logistics now. Or not touch my calipers as others have suggested. Ordered new ARP Studs for now. Almost cross threaded caliper bolt last time changing rotors. Never had an issue- until this last time. Very unnerving.
05-22-2018, 08:14 PM
#5
Rennlist Member
My thoughts on calipers is to buy new ones and sell the old ones.
Cost difference including the new parts and your time will help you decide.
I did studs when I went to new calipers as I had to time-cert one of the uprights.
Cost difference including the new parts and your time will help you decide.
I did studs when I went to new calipers as I had to time-cert one of the uprights.