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Disc Brake Maintenance Tips and Tricks


CaffeineRacer

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So I'm putting a set of fresh pads and rotors (turned, but still within spec) on my Avanti and I was wondering if anyone has any tips or tricks for achieving quiet braking?

These are the things I have read about from various sources, but have never tested first hand.

1). Chamfering the leading and trailing edges of the brake pad

2). Applying some sort of dampening material (lube or that orange rubbery type stuff [e.g. CRC disc quiet]).

3). Crosshatching the rotor surface to achieve better bedding of the pads and rotors

4). ?

Anyone ever try any of these or others?

Also I had one hell of a time getting my pads to come out last night, they were really rusted in there (the brakes are otherwise in fantastic shape). Is this fairly common?

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Make sure the calipers are properly shimmed or they can make noise. I'm not sure of the procedure...hopefully the shop manual gives instructions or someone else here can do so.

Some of the reason for noisy Avanti brakes is due to the disc pad materials available today. Most of the pads available today are noisy as brake pad makers don't really put their best technology into such an old and obsolete application with little sales volume and EPA regs probably prevent the use of original materials. If you can find a set of NOS original pads you should be ok. I understand there is a new pad out with top technology but I don't know who the company is supplying it.

When my '70 was rebuilt, the brakes were so noisy it was embarrassing. Several sets of pads didn't help...carefully installing them properly didn't help...chamfering the edges didn't help...disc quiet didn't help. The only thing that helped my car was installing the Turner conversion kit.

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NOT SO!!!!! EBC makes some of the finest brake pads available, and you will think you have the newest Brembo Calipers !

Just order for a Jaguar and order the Green Stuff pads for the street. It will make a noticeable difference.

I will find the part #s and post here in the next day or so.

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I recently went through mine, and here's a few things I'd suggest. Obviously, check your wheel bearings. While you have it apart, consider removing and replacing the 3 bolts that hold the bracket to the spindle. If these happen to come loose, all kinds of nasty things can happen! Also replace the two caliper retaining bolts with new grade 8 bolts. Torque them to specs. Just cheap insurance and it shouldn't cost you more than a few bucks.

When you take off the caliper bridge, pay close attention to how many spacers there are and where they go. When you mount it back up, notice that the vertical bar on the bridge lines up with the face of the rotor? You can use that for a reference point to get your caliper centered. Take a straight edge on the face of the rotor and line it up with that bar, which should be about the same thickness as your rotor. I got this tip from Gary Johnson, and it was very helpful when I did mine. Once you have that pretty much centered, you can start taking some measurements with a feeler gauge. There's been a lot written about this on Bob Johnstone's site:http://www.studebaker-info.org/tech/brakes/calipers.html

I actually like the Dunlop/Bendix disc brakes, and mine work just fine with no noise at all. I agree with Brad, though. Get the EBC Green Stuff pads. Amazon has a good price on them. Another friend got some from SI and they were unusable, according to him. He went with the EBC's and seems to like them.

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Brad and Warren, thanks for the tips. I did some checking does "DP2120" sound like the correct part number? I noticed EBC says these are made for sport compact cars wth less than 200 hp. I'm guessing that's being overly cautious. I did buy some from SI, but it's obvious that they are a very high metallic compound so I'm going to give the EBCs a go. I unfortunately have some time before this seemingly simply project will be complete because I broke one of the bolts off that holds the position to the caliper and I'm trying to figure out how to extract it with having to oversize the hole and retap. Ugh, why do little projects always turn into big one!

Warren, what is the bridge you are referring to? Do you mean the Pad retainer?

Edited by CaffeineRacer
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No, the bridge is the cast iron piece that your cylinders are mounted to. When it's all assembled and on the car, look straight at your caliper in line with your rotor. I think you'll see what I mean. Here's the best picture I can find. See where the bolt goes through that bar in the middle to hold the pad retainers? That bar should line up with your rotor.

th_20141103_134035_zps2wzs5gcy.jpg

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I actually didn't install those pad in mine, since mine were like new. A friend did, and I can't recall if he had to sand them to get them in. Getting the cylinders completely compressed can be a challenge, though. I had to apply a bit more force than I would on a normal piston.

I wouldn't worry about any adhesive or shims. If they fit onto the head of the piston snugly, you should be fine.

I do recall they have a break in layer on the pads and a pretty specific break in method listed in the instructions.

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So it took a bit to fit them in there. EBC needs to give their QC guy a swift kick in the ass. There was quite a bit of variation in width of the backing. I had to sand down the sides of all of them and one I even had to take my dremel too.

Anyway they're in there and now I've got new problems; a leaking piston seal. So now I've got to either rebuild or replace that one. :-(

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I was lucky, none of mine leaked. Do yours happen to say Sumitomo on the cylinder? I have a feeling that Avanti Motors started using them in the later years.

You have a few options, and the cheapest would be a rebuild kit but there is a good chance you'll find some severe pitting inside unless you've been using silicone brake fluid.

Rebuilt and sleeved cylinders are available for about $100 each, and apparently you can still buy new ones from Nissan. They used them in the old Fairlady and 2000 roadsters.

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I have the same brakes on my "E-Type". When you remove the piston from the leaking cylinder there is a 99% chance you will find some pitting.

You can buy stainless steel replacements from XKS Jaguar in Calif.

However I tried spinning one in a lathe with #400 then 600, then 1000 grit wet or dry sand paper using brake fluid as a wetting agent.

I then took Simichrome metal polish to finish it.

This doesn't remove any measurable amount of metal and the pits were still visible. However since they don't use "Lip seals" but a type of "O" ring it sealed well. I tried this several years ago and it is still holding just fine.

Considering the cost of new or "Sleeved" cylinders this is worth a try

Charlie RQB3921

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Agreed. I would love to own a series 1 roadster one day!

Charlie, thanks for the tips. I've no access to a proper machine shop so I'll have to wait for another day to try out your method.

I think I'll go ahead order a complete one. Does anyone know if the ones SI sells are NOS, rebuilt, or what? Also last question but does anyone have a parts catalogue and can tell me the pn for the bolts that hold the piston to the caliper bridge? They're a goofy 1/4-28 bolt with an undersized hex head.

To rich for my blood, but there is also this company. They sell brand new stainless steel calipers and offer them in a 2.25 size which apparently will fit our stock setup and give a little more stopped power. http://www.hyedracyl.com/studabkr.html

Edited by CaffeineRacer
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If you want to buy a new one, here's one that's probably the same as you have now: https://www.studebakerparts.com/studebakerparts/store/s/agora.cgi?product=brk4&cart_id=4704.31055

For another $40 you can get the stainless one here:http://xks.com/i-6916970-gr-64932067ss-wheel-cylinder-2-1-8-stainless-steel.html

Edited by warren55
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If you want to buy a new one, here's one that's probably the same as you have now: https://www.studebakerparts.com/studebakerparts/store/s/agora.cgi?product=brk4&cart_id=4704.31055

For another $40 you can get the stainless one here:http://xks.com/i-6916970-gr-64932067ss-wheel-cylinder-2-1-8-stainless-steel.html

Thanks warren. I ended up ordering a new one from Myer's studebaker as well as the bolts. Jon said the ones he sell are actually new units for some Japanese car. Which is a bummer since it won't say Dunlop like the originals. I'll probably try and rebuild the one that's on there and swap it out eventually, but in the meantime this is a good solution.

I sure am glad Bendix used dunlops brake design so we can poach off of the e-type parts out there.

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They may say "Sumitomo" on the calipers which were a licensed Bendix/Dunlop product. Avanti Motors used them on many of their cars...my '70 among them. Whether they were less expensive than buying Bendix, an availability thing or maybe even Bendix discontinued them I can't say. Regardless, if what you're buying say "Sumitomo", it will be what the factory installed.

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I agree, Avanti Motors must have started using those because of availability or price. That's what mine has on it, too. Those are the ones that are still available from Nissan if you know what to order. I also hear that the casting is too thin to sleeve.

I think you can see where it says Sumitomo on the top of my cylinder in this picture.

http://s3.photobucket.com/user/wcortesi/media/20141103_114230_zpsbaa52fe9.jpg.html

Edited by warren55
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It may simply have been an availability thing or maybe they didn't always rotate inventory to use the oldest parts first. I know some Avanti II's...even after mine was built...had tapered axles rather than flanged axles installed. I think whomever was pulling parts for any particular car being assembled just pulled the easiest to reach and sometimes that was an older part and sometimes it was a newly sourced part.

Your Dunlop marked calipers may simply have been sitting on the back of the shelf for a long time before being pulled. 1982 was about the time Steve Blake was negotiating to buy Avanti Motors and the Altman and Newman families may not have been investing any more financial outlays into running the company than they had to knowing they wanted out.

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  • 2 weeks later...
  • 3 weeks later...

Just curious if you got the job done yet? Always nice to wrap these things up!

Thanks for the reminder. I took three steps back, but have made progress forward and am almost done.

I order a new cylinder to replace the one leaking one, with the intention of rebuilding the old one eventually and reinstalling it. Well took it out for a few short drives and all was fine until the last longer one i took. I had to step on the brakes hard and noticed the car pulled really really hard to the left (the brake piston I had replaced was on the right). I figured, crap, I must have not tightened a fitting well enough and it was leaking fluid. Anyway I get home and sure enough there was brake fluid all over the right calipers. I figured I would take care of it that night when I got home.

When I get home and go into the garage there is a 3 foot puddle of brake fluid in front of the right tire. Super crap! Now the other caliper piston (the one on that side I hadn't replaced was leaking, a lot!!). So I just decided I was done screwing around and ordered 3 more brake pistons and all new hard lines and another set of EBC green stuff brake pads (because the other ones were ruined by all the brake fluid). Now all that is all installed and the brakes were bled, but I'm still not happy with the brakes. I went out and got a pressure bleeder now (Motive pn# 0105) and I'm just going to flush the whole system (front and back) and hopefully that will get me back to a good solid brake feeling. Moral of the story, I don' t know, but this has been one hell of an expensive brake job!.

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That is the problem with these old brake systems; the parts are available but a little pricey! At least you'll know that everything is mostly new and shouldn't give you any trouble for many years. If you're using regular brake fluid, it's a good idea to at least bleed them every year or so to keep fresh brake fluid in the pistons. They can rust up inside and cause all kinds of trouble.

Let us know how it goes!

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