Rebuilding "63-'64 Dunlap Calipers

[John E. Priester]

Guessing this has been addressed before but here goes.  I am trying to rebuild the original Dunlap calibers on my 63.  When I attempt to pull the caliber piston out of the housing I get A LOT of resistance from the piston sliding off the center pin.  Also when I attempted to put the piston back in after lubricating the new seals and pin with new brake fluid, had to press it in with an arbor press.  Stoppewd  after a 1/2" as this seems wrong.

Would like to rebuild them in lieu of the $150 per caliber it cost to by new/rebuilt ones but I would like to have "Sophia" stop reliably once I get her back on the road.  Any thoughts?  More info needed to answer?  

Thanks in advance and all have a Merry Christmas and Great New Year.

John Priester

 

[StudeNorm]

I would always check Bob's Studebaker resource site before pretty much anything else when I decide to dive into a new project http://studebaker-info.org/rjtechdec2017p1g.html. This is a great resource for any info you might need. It has so much info it is a little daunting to get around but after using it for a while it starts to make sense...

[silverstude]

You should blow them out with air pressure into the bleeder port

 

[PackardV8]

Having the Avanti Shop Manual in hand is always my starting point.

jack vines

[mfg]

At this point in time, the only Dunlop  disc brake cylinders I've had any luck rebuilding (new seals) are ones that have previously been stainless steel 'sleeved'.

Original (non-sleeved) ones always seem to have some corrosion due to water absorbing (DOT 3) brake fluid.

Frankly, I definitely understand why anyone who is still actually DRIVING a disc brake equipped Studebaker upgrades to a modern floating caliper ventilated disc brake!

[PackardV8]

15 hours ago, mfg said:

Frankly, I definitely understand why anyone who is still actually DRIVING a disc brake equipped Studebaker upgrades to a modern floating caliper ventilated disc brake!

Frankly, it's difficult to understand why anyone is still actually DRIVING a Studebaker/Avanti at all.  Literally every mechanical part is antique by modern standards.  Once one upgrades the brakes, then the need for an overdrive transmission becomes apparent, as does EFI.  It's impossible to make a new car out of an old one.

When the Studebaker disc brakes are rebuilt with all new wear parts, they're actually better than any other mechanical part of the car.

 

jack vines

[Rob Dudley]

If you can't rebuild the old cylinder just get a new one. You're trying to save $150 dollars on your $20,000 dollar investment. The sleeves can and do slip and the time it will be tested is during an emergency stop. I just threw out a pile of sleeved cylinders that had slipped since the originals are available again. One of mine slipped just in normal use after being in use for a number of years. In new condition the originals do work very well although they won't dissipate heat as well as modern designs, allowing for fading during intense workouts. 

Rob

 

[StudeNorm]

25 years ago I had a sleeve push out one night coming down a hill in my 62 GT. Ended up in the ditch. My Avanti has had DOT 5 fluid in it for at least 30 years and has worked flawlessly since I got it 5 years ago. I got a box of brake rebuild parts when I bought the car so I know the cylinders were rebuilt back in the day.

[mfg]

5 hours ago, PackardV8 said:

Frankly, it's difficult to understand why anyone is still actually DRIVING a Studebaker/Avanti at all.  Literally every mechanical part is antique by modern standards.  Once one upgrades the brakes, then the need for an overdrive transmission becomes apparent, as does EFI.  It's impossible to make a new car out of an old one.

When the Studebaker disc brakes are rebuilt with all new wear parts, they're actually better than any other mechanical part of the car.

 

jack vines

Well, I guess if I were trying to prop up one of those '55-'56 Packard V8's I'd also be feeling quite negative about driving older vehicles!......Driving an Avanti is a pleasure I partake every day!

Don't forget ....when we're gone, someone else will surely be driving our cars!!

[mfg]

As far as stainless steel brake cylinder sleeves slipping.....instead of blaming the sleeves, I think you boys need to question the technician who did the job.

PROPERLY INSTALLED stainless cylinder sleeves don't "push out"!

[PackardV8]

18 hours ago, mfg said:

Well, I guess if I were trying to prop up one of those '55-'56 Packard V8's I'd also be feeling quite negative about driving older vehicles!......Driving an Avanti is a pleasure I partake every day!

Don't forget ....when we're gone, someone else will surely be driving our cars!!

FWIW, I own and drive a Studebaker Avanti.  I'm just not under the mistaken impression that the OEM brakes are unrepairable/unreliable and must be thrown out.

My other driver is a '55 Studebaker E12 3/4t also with the original brakes.  With a Packard Caribbean V8, in it, it runs rings around Studebaker R1s.  It's all good.

jack vines

Edited December 22, 2018 by PackardV8

[mfg]

I've always gotten a kick out of folks who believe technology ended with the invention of the Dunlop disc brake.............and 6 volt automotive electrical systems!!

Be well Jack!

[studegary]

2 minutes ago, mfg said:

I've always gotten a kick out of folks who believe technology ended with the invention of the Dunlop disc brake.............and 6 volt automotive electrical systems!!

Be well Jack!

I probably shouldn't get into the middle of this.  With that said, I do believe that Jack neither said nor implied that technology ended there.  He was just referring to keeping what the vehicle came with in good condition.  If we wanted the latest technology, we would all drive new cars.  I have owned and enjoyed restored cars, restomods and new cars (none new in the past 18 years).    

[mfg]

2 minutes ago, studegary said:

I probably shouldn't get into the middle of this.  With that said, I do believe that Jack neither said nor implied that technology ended there.  He was just referring to keeping what the vehicle came with in good condition.  If we wanted the latest technology, we would all drive new cars.  I have owned and enjoyed restored cars, restomods and new cars (none new in the past 18 years).    

And I agree with your first sentence Gary!

[StudeNorm]

On ‎21‎/‎12‎/‎2018 at 3:48 PM, mfg said:

As far as stainless steel brake cylinder sleeves slipping.....instead of blaming the sleeves, I think you boys need to question the technician who did the job.

PROPERLY INSTALLED stainless cylinder sleeves don't "push out"!

Ed, I was relating a story that happened to me around 1989 or so, back when sleeved calipers were fairly new in the market. I am blaming the sleeves but who can know if it was bad machine work or bad manufacturing procedures or bad installation or?....

I am not sure who you mean when you say "technician who did the job". The rebuilt/sleeved calipers were ordered through Newman and Altman and I expect they had some 'technician' installing the sleeves into the calipers. I had a licensed auto mechanic install the calipers on the car and I know he did a proper job. The fault was definitely with the caliper and there was no way to know that it was going to fail until it did. I paid my money, took my chance and lost. At least the damage was minimal and I did get a replacement caliper no charge...

Have yourself a great day and a Happy New Year!