55.2-59 caliper ID

[FAKKY]

So its been 3 years since I started the truck build ...... and starting to get closer to end than beginning --- but as hooking up brake lines I pulled the calipers to test with compressed air - and no movement with over 100psi.




Anyone know how to ID these ?
They are off a dodge dakota ....... but forget specifically which year.

[mongocanfly]

Looks like this 91 in the pic...https://www.carparts.com/details/Dod...8aAsK6EALw_wcB

[MiraclePieCo]

Only 100 lbs?

With the correct master cylinder in place, the pedal ratio must be great enough to produce 1200 psi system pressure under severe braking conditions.

https://www.markwilliams.com/braketech.html

[1project2many]

Most GM caliper pistons will move with air pressure. But Chrysler?? Not so sure.

[FAKKY]

Originally Posted by mongocanfly

Looks like this 91 in the pic...https://www.carparts.com/details/Dod...8aAsK6EALw_wcB

Ended up going to the carparts store an measuring bore size and travel and castings and looks like a 93 (which is probably the same as 91). Just wasnt sure if the casting#'s meant anything - I couldnt find anything.

thanks !!

[FAKKY]

Originally Posted by MiraclePieCo

Only 100 lbs?

With the correct master cylinder in place, the pedal ratio must be great enough to produce 1200 psi system pressure under severe braking conditions.

https://www.markwilliams.com/braketech.html

My compressor bombs out at around 120psi.

Wasnt really sure of another way to test until it was hooked to MC. After coming from a junk yard and sitting for 3 years in my shed - just decided to spend the $50 to be sure ...... good point tho.

[FAKKY]

So when fiddling with the NEW caliper - I added 100psi and blew out the piston. No biggie I thought and folded it all back in until I noticed the outer boot had a crack in it. Im going to assume it happened when I shot it out. #backyardmechanics

Is the boot just a dust protector ? Seems the seal is more the piston and inner cylinder itself ..... but not sure.

[FAKKY]

just bought 2 new boots ..... will replace just to be sure no dirt/water gets in

[1project2many]

1) Pistons are installed with a C clamp and hand pressure. I would be surprised if one doesn't move with air pressure applied.

2) The cover is a dust boot. But without it the seal generally does not live a long life.

3) If you ever want to test the piston with air again, use a block of wood as a piston stop.

[Russell Ashley]

I just started reading this thread and was going to say that you were probably lucky that it didn't move, but then I read farther and saw that you found out what happens when it does move if there's nothing to stop it. Best teacher, experience.

[mr48chev]

Yep, 91/92 or So Dakota. These are off a 92 Dakota I took them off when I had plans to run an Industrial Chassis crossmember but didn't get one before he quit making them.

Shop cat still isn't happy that I stripped and sold the Dakota as he slept in it for a while after I sold a door glass off it.

[FAKKY]

Thats funny - shopcat.

So I bought the capiper rebuild kit ... and have tried both ways to put the boot on - ruining another one in the process so down to last one.

1) Seat the piston fully. Get the boot on the ring/groove. Then push down the boot edge to sit.

2) Piston out. put the seal on the groove and then seat piston and push in keeping everything center.

Neither appraoch made much difference ..... this is what I end up with. Im thinking of just going like this and seeing waht happens since that piston doesnt travel that far. But thoughts or tips ?

[FAKKY]

wife had a go with her fingernails ...... better


At least flush with piston now

[mr48chev]

Along with front end repair and alignment I did brake jobs for a living for several years. I still hate rebuilding calipers and have had that same fight just about every time. I don't have a good answer either.

[Driver_WT]

I have found it easier to buy the rebuilt calipers and for most vehicles not much more money. Just picked up a set of calipers for the front of the S10 chassis under my 53 Chevy truck for $34 each side. Bolted on in less than 30 mins.

Wade