A few brake caliper refinishing questions
#31
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Well, I thought I'd give everyone an update:
All calipers have been rebuilt with new seals. New brake lines are already installed on the car. I decided not to refinish the rear calipers, as they are too nice still - they only needed a few minor touch-ups.
The fronts needed the refinish badly. However, it took three attempts to get a decent finish with the G2 epoxy.
First I tried to brush it - and got unevenness and runs. It just didn't look right.
Then I tried with a Preval sprayer - but the epoxy is too thick and increasingly clogged it. Since I had only one sprayer, I could not finish this job.
The manufacturer had told me that their epoxy cannot be thinned, so I did not try the Urethane reducer (maybe that was a big mistake - has anybody actually done it that way?). They suggested to brush, and use the sprayer only for their metallic finishes.
Then I spoke with Ron_H again, and he gave me the most crucial hint: Have multiple Preval Sprayers handy, and fill one nof the glass containers with Acetone to clean the sprayer inbetween.
That's exactly what I did today. And it worked pretty well.
The sprayers get clogged after spraying about 1/3 to 1/2 of a caliper. They also get cold and lose pressure a bit. So I alternated between two sprayers, and cleaned them by spraying acetone on a piece of cardboard whenever they began to clog.
I can't say it is 100% smooth everywhere, but all is covered and there are no runs. The calipers look 100% better than before. I just need to spray on the white PORSCHE, and I'm done.
Now, I do have one question:
I did not mask-off the contact surface where the caliper screws on to the steering knuckle. Should I sand off the finish in this area before mounting the caliper?
All calipers have been rebuilt with new seals. New brake lines are already installed on the car. I decided not to refinish the rear calipers, as they are too nice still - they only needed a few minor touch-ups.
The fronts needed the refinish badly. However, it took three attempts to get a decent finish with the G2 epoxy.
First I tried to brush it - and got unevenness and runs. It just didn't look right.
Then I tried with a Preval sprayer - but the epoxy is too thick and increasingly clogged it. Since I had only one sprayer, I could not finish this job.
The manufacturer had told me that their epoxy cannot be thinned, so I did not try the Urethane reducer (maybe that was a big mistake - has anybody actually done it that way?). They suggested to brush, and use the sprayer only for their metallic finishes.
Then I spoke with Ron_H again, and he gave me the most crucial hint: Have multiple Preval Sprayers handy, and fill one nof the glass containers with Acetone to clean the sprayer inbetween.
That's exactly what I did today. And it worked pretty well.
The sprayers get clogged after spraying about 1/3 to 1/2 of a caliper. They also get cold and lose pressure a bit. So I alternated between two sprayers, and cleaned them by spraying acetone on a piece of cardboard whenever they began to clog.
I can't say it is 100% smooth everywhere, but all is covered and there are no runs. The calipers look 100% better than before. I just need to spray on the white PORSCHE, and I'm done.
Now, I do have one question:
I did not mask-off the contact surface where the caliper screws on to the steering knuckle. Should I sand off the finish in this area before mounting the caliper?
#32
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I understand a coat or two of epoxy can get thick, but can't imagine 2-3mm causing any problems. Brake pads are a floating assembly anyway, so there is room for compensation.
Get some pics up when you have a chance.![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Get some pics up when you have a chance.
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
#34
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Nicole--
Clean the paint from the mating surface. Takes seconds with the abrasive wheel on the Dremel. Paint there will possibly interfere with your ability to maintain proper torque/tension on the mounting bolts. May or may not be critical, but why risk it?
Clean the paint from the mating surface. Takes seconds with the abrasive wheel on the Dremel. Paint there will possibly interfere with your ability to maintain proper torque/tension on the mounting bolts. May or may not be critical, but why risk it?
#35
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Today I had some time to spray the PORSCHE lettering onto the refinished front calipers. Interestingly, the stencils I got through eBay are
1. Different from the original lettering on the calipers
2. Too large for the lettering area of the rear calipers (which I ended up rebuilding but not not refinishing).
Take a look at the pictures below - from top down: Rear caliper, original caliper, refinished caliper. Then a close-up of one of the refinished ones.
For the white lettering I used a Rustoleum high temperature paint (supposedly withstanding up to 1200 Degrees).
Now all calipers are ready to be reinstalled. Can't wait...
1. Different from the original lettering on the calipers
2. Too large for the lettering area of the rear calipers (which I ended up rebuilding but not not refinishing).
Take a look at the pictures below - from top down: Rear caliper, original caliper, refinished caliper. Then a close-up of one of the refinished ones.
For the white lettering I used a Rustoleum high temperature paint (supposedly withstanding up to 1200 Degrees).
Now all calipers are ready to be reinstalled. Can't wait...
Last edited by Nicole; 09-28-2008 at 05:35 AM.
#36
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Hi Nicole....I know it's a bit late to tell you this but....I refinished my calipers about 4 years ago. I sandblasted them...( acually used ground walnut shells) Then applied primer and finally used the exact same enamel that the car was painted with. High heat or special paint IS NOT REQUIRED!!! After 4 years, the calipers still look as good as they did after I refinished them. I will take some pics and post them here after while as long as the rain holds off so I can bring the car out of the garage to take the pics. Just my .02
#37
Instructor
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Hi Nicole ,
there are two different Porsche fonts :
The old one used til the late seventies (?) , and the new actual porsche font.
The new font has longer letters .
Greetz,
Thommy
#38
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I think the lettering looks great. Not many people would know the difference unless it was pointed out. I like the idea of using hi-temp paint especialy if the calipers are cleaned on a regular basis (which is something I do when cleaning the wheels) and as my rear caliper paint is flaking off. Good job
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#39
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We put all four calipers back on this afternoon, along with the new brake lines. Looks great! Bled the whole system, test drove - and the pedal was soft, with the pressure point too far down. We must have missed some air, but did not have time to bleed the whole system again. Hopefully we can figure out to squeeze this in in the next days. Can't wait to drive the car again!
And I broke yet another brake pad sensor... These things frustrate me to no end! The material is so brittle that if you have to push them onto the pad, they crack and break. I wish someone would come-up with an aftermarket replacement that is less sensitive.
And I broke yet another brake pad sensor... These things frustrate me to no end! The material is so brittle that if you have to push them onto the pad, they crack and break. I wish someone would come-up with an aftermarket replacement that is less sensitive.
Last edited by Nicole; 09-29-2008 at 04:42 AM.
#40
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I totally agree!! I have broken my share. Nice work Nicole!
#41
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Nicole how old is the master cylinder? I would guess that you bled this first? There is a chance that your master has weak seals, or they could have gotten damaged by pushing the brake pedal to the floor in the unused portion of the master bore and this will push the seals into any debris in the bore.
I just put a master into my Euro , bled the master then the calipers and the pedal is hi and hard, I also used ATE super blue, also i replaced the rear brake proportioning valve as it was filled with rust
Nice job on the repaint job and the lettering, knowing your level of perfection I can appreciate all of your hard work to do this job
I just put a master into my Euro , bled the master then the calipers and the pedal is hi and hard, I also used ATE super blue, also i replaced the rear brake proportioning valve as it was filled with rust
Nice job on the repaint job and the lettering, knowing your level of perfection I can appreciate all of your hard work to do this job
#42
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Hi Stan:
The master cylinder is as old as the car - 101728 miles today. The brake pedal has a strong resistance as usual, but much further down the pedal travel.
In other words: Normally, the pressure point is a bit higher than the gas pedal, but now it's lower.
We plan to bleed again on Thursday or the coming weekend.
The master cylinder is as old as the car - 101728 miles today. The brake pedal has a strong resistance as usual, but much further down the pedal travel.
In other words: Normally, the pressure point is a bit higher than the gas pedal, but now it's lower.
We plan to bleed again on Thursday or the coming weekend.
#43
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So try bleeding the master first with a pressure bleeder
#44
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Hi Nicole, all sounds normal to me. Having recently refurbed my own calipers I have had to bleed them twice. Brakes felt fine but with too much travel to the pedal *** you said - bit *** clenching on the test drive. Bled them again after a couple of days and they have been fine since. I think that it just takes time for some of the trapped air to work its way through the calipers.
#45
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Remind me real quick: Bleed the inside or outside of the calipers first?
I think we did inside-outside. The caliper sequence was passenger rear, then driver rear, then passenger front, then driver front. We did bleed the master cylinder twice.
I think we did inside-outside. The caliper sequence was passenger rear, then driver rear, then passenger front, then driver front. We did bleed the master cylinder twice.