Questions about caliper rebuild

[MarkA]

Hey all,

I am doing brake work on my 67 bj8. The front calipers have old rubber. I was thinking about doing a rebuild on them since I need to already change the seals. They don't seem like they have any problems. They just have old parts.

Are there any tricks or hint when rebuilding these things? The manual says not to split the calipers at the seams. Is this still true? Any other comments would be welcomed.

Thanks,
Mark

 

[Patrick67BJ8]

Hey all,

I am doing brake work on my 67 bj8. The front calipers have old rubber. I was thinking about doing a rebuild on them since I need to already change the seals. They don't seem like they have any problems. They just have old parts.

Are there any tricks or hint when rebuilding these things? The manual says not to split the calipers at the seams. Is this still true? Any other comments would be welcomed.

Thanks,
Mark

Mark,
I did my calipers a few months ago and I did split the calipers to put the rubber seal that goes between the two halves. This seal didn't come with the rebuild kit and was purchased separately. I also put in new pistons. The standard are about $20.00 each and the stainless are about $30.00. Don't forget to renew the hoses too. I guess that just about gulps up all your beer money...sorry.
Patrick

 

[MarkA]

I already hid a bottle so that will be safe. I will make sure to order the seal between the two halves. Do stainless pistons make a lot of difference over the others?

Mark

 

[Patrick67BJ8]

I already hid a bottle so that will be safe. I will make sure to order the seal between the two halves. Do stainless pistons make a lot of difference over the others?

Mark

I don't believe they really make a big difference. That's the reason I didn't buy them. If you're using silicone brake fluid the originals should last at lot longer than they did the first time. But, if you're taking them all the way apart and you got an extra $40.00 you can't go wrong. Of course $40.00 does buy a real good bottle.I painted mine red while they were apart. Should have had them powdercoated. The red calipers is the same color as those real expensive ones that are used on those real expensive cars and come to think about it, I think the red color really does makes them work a lot better.

 

[shorn]

FWIW, go stainless

 

[MarkA]

Yeah Patrick,
Red works OK... but I heard that chrome is better! /bcforum/images/%%GRAEMLIN_URL%%/laugh.gif

 

[bob hughes]

You need to be a gorilla to undo the bolts to split them and equally so when putting them all back together. You may also require the Patience of Job when trying to locate the dust covers.

Experience has shown me to check carefully for leaks after installation onto the car, push the brake pedal several times then have a look around. I have had a replacement set that did leak because of a trapped seal in the rebuilding of the calipers by experienced people.

Bob

 

[suprgnat]

I did my calipers a few months ago and I did split the calipers to put the rubber seal that goes between the two halves. This seal didn't come with the rebuild kit and was purchased separately. I also put in new pistons. The standard are about $20.00 each and the stainless are about $30.00. Don't forget to renew the hoses too. I guess that just about gulps up all your beer money...sorry.
Patrick

From whom did you purchase the rubber seal, and what did you torque the bolt to?

TIA

Paul

 

[Randy_Gay]

I got the little seal from Pegasus racing. I don't remember hoe tight on the bolts. I used loctite and cranked down pretty hard.

 

[Patrick67BJ8]

I did my calipers a few months ago and I did split the calipers to put the rubber seal that goes between the two halves. This seal didn't come with the rebuild kit and was purchased separately. I also put in new pistons. The standard are about $20.00 each and the stainless are about $30.00. Don't forget to renew the hoses too. I guess that just about gulps up all your beer money...sorry.
Patrick

From whom did you purchase the rubber seal, and what did you torque the bolt to?

TIA

Paul

Bitish Car Sprecialst in Stockton, CA has the seals at about $3.00 each. Tighten the bolts tight!! Crank down on them, but remember that cast iron can strip!! Try to get them as tight as you remembered taken them off. I can't tell you what the true specs are for the torgue. Maybe someone on the forum has them??
Patrick

 

[John Loftus]

From whom did you purchase the rubber seal, and what did you torque the bolt to?

Hi Paul,

When I purchased my SS caliper pistons from John Farrell Auto Parts, I also purchased the rebuild kit w/the caliper seals. I asked him about replacing the bolts and torque and this was his answer:

---------

I don't think the original bolts are avail. They were a special bolt with a slight difference in pitch on the threads to act as a locking bolt. I recommend you use a good quality Loctite on the threads and torque to about 38 ft. lb. I have never had a problem with the calipers in 30 years doing it this way

Regards
John
John Farrell Auto Parts

 

[Randy Forbes]

From whom did you purchase the rubber seal, and what did you torque the bolt to?

Hi Paul,

When I purchased my SS caliper pistons from John Farrell Auto Parts, I also purchased the rebuild kit w/the caliper seals. I asked him about replacing the bolts and torque and this was his answer:

---------

I don't think the original bolts are avail. They were a special bolt with a slight difference in pitch on the threads to act as a locking bolt. I recommend you use a good quality Loctite on the threads and torque to about 38 ft. lb. I have never had a problem with the calipers in 30 years doing it this way

Regards
John
John Farrell Auto Parts

Good suggestion. I would hope that someone would look at the markings on the bolt head/+diameter and find a suitable torque chart before going off on the thing.

I've been rebuilding Girling and Lockheed calipers for decades and have never had any issues after splitting the halves.

Always use the correct square section seal between the halves though, as the common variety O-rings don't fill the bill. One of the things I do after a rebuild is pressurize the chambers with a hand pump and a block of wood between the pistons. I generally use 1500-2000 psi, and it should hold the pressure indefinately (until intentionally released).