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Old 07-03-2020, 02:46 PM   #1
R32RennSport
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Default Vintage Brake Upgrade

Vintage Brake Upgrade Help!

OK, before I get flamed for not using the search function here and on Google I haven't really found quite what I'm looking for.

To preface this here is what I'm working with:

A recently completely rebuilt, replaced or overhauled system, front to rear, 1966 single circuit Amazon. Also to note, the braking performance marginally improved post overhaul so it seems it was in pretty good condition to start. With power output significantly increased, wider tires and higher freeway cruising speeds I am now looking for a slight improvement in braking performance. My main complaint is I can't lock up the front tires no matter how hard I try at any speed, the rears will lock up if I can create enough weight transfer but rarely lock up as well.

What I want:

More braking performance without doing an aftermarket conversion kit (cost and I want to stick with 15 inch rims) and preferably without adding the complexity of a brake booster (want to keep the engine bay simple and like manual pedal progressive feel). What I'd like to start with is experimenting with master cylinders because of 1) simplicity 2)cost 3) I like the progressive feel of manual versus boosted system (also I have great leg strength so that's not an issue yet, maybe in another few decades )

If anyone has done this and can give me both info and feedback. If you can give me specifics on which master you used and bore size that would be great. I'm not against splitting the system into a dual circuit but with using current components preferred.
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Old 07-03-2020, 03:06 PM   #2
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Something's wrong if you can't lock the brakes. Either the rotors and pads are glazed or you have air in the system. A proportioning valve was added to the system in '67 and is a good idea for spirited driving.

Have you looked into performance friction materials?

https://www.porterfield-brakes.com/P...0Manufacturers
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Old 07-03-2020, 03:38 PM   #3
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I should have thought of performance pads first. All the friction materials are new (OE compounds) and it does have the single proportioning valve in the rear which I rebuilt as well.

I'll start with pads and go from there. Pedal feel is great, it does stop just not as quickly or aggressively as I'd like. I know there isn't any air in there.
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Old 07-03-2020, 03:42 PM   #4
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Originally Posted by hiperfauto View Post

Have you looked into performance friction materials?

https://www.porterfield-brakes.com/P...0Manufacturers
Holy crap those are as expensive as the track pads for my R32
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Old 07-03-2020, 03:53 PM   #5
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Porterfield's R4S compound is rotor friendly, has good cold performance and is the most affordable of the pads listed. I run them in my 140 and 240 and they work well.
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Old 07-03-2020, 03:58 PM   #6
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Porterfield's R4S compound is rotor friendly, has good cold performance and is the most affordable of the pads listed. I run them in my 140 and 240 and they work well.
My bad, I didn't scroll down far enough

I've also heard great things about EBC pads from what I recall when I was working for a British sports car shop. Maybe I'll cross shop the two and see what I like.

Thanks again. I'll report back here after a pad swap to compare notes!
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Old 07-03-2020, 04:42 PM   #7
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Pro tip, call the order in directly to Porterfield and ask about promotions. If you're a first time customer you get a 10% discount! Nice they are just down south, I should see them mid week!
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Old 07-04-2020, 04:29 AM   #8
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My bad, I didn't scroll down far enough

I've also heard great things about EBC pads from what I recall when I was working for a British sports car shop. Maybe I'll cross shop the two and see what I like.

Thanks again. I'll report back here after a pad swap to compare notes!
The genuine Volvo pads are very good and cheap.
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Old 07-06-2020, 12:03 PM   #9
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Thank you for taking the time to respond everyone, much appreciated. I'm definitely in no way interested in changing out my calipers and/or rotors unless it was something that made sense (as in cheap availability) and retained the original lug pattern and 15 inch wheel fitment. I think someone figured out how to put Ford Ranger brakes on an Amazon without much fuss but I haven't revisited that yet.

I'm running cheap 400 tread wear 205 section tires and OE equivalent Mintex or PBR pads (don't recall which, but definitely a stock compound). I'd like to start with pads and hydraulics before adding a booster or even considering a system swap as I stated before. The brake system currently has weak initial bite and zero lock up when cold. The bite is better when it gets hot on a spirited drive and/or at autocross but still not enough to lock up the front under hard pedal pressure, will eventually lock up rears with enough weight transfer. My pedal does feel OK, but I find as it gets hot that a double pump to set the pads is usually required, not that I have to but the pedal starts to feel weak. No leaks anywhere, I've bleed and adjusted rear shoes, fluid level has remained constant, new master, new lines front to rear, rebuilt both calipers and proportioning valve.
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Old 07-09-2020, 03:43 AM   #10
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What did you do with the brake system refurb? From what you describe it does seem like there is something amiss with your standard setup so probably worth double checking it. What thickness were the discs, are they still in tolerance? Master cylinder in good shape? Might be worth bleeding the brakes again to be 100% sure there is no air in the system. No small weeps anywhere?
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Old 07-09-2020, 09:40 AM   #11
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I would recommend a GG rated Organic pad. Great initial bite and plenty of heat load. Downside is that they are usually dusty.

http://faculty.ccbcmd.edu/~smacadof/DOTPadCodes.htm

Did you replace all the rubber lines when refreshing your brakes? Rubber lines fail internally so it is hard to tell if they are worn out.
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Old 07-09-2020, 09:51 AM   #12
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Quote:
Originally Posted by R32RennSport View Post
Thank you for taking the time to respond everyone, much appreciated. I'm definitely in no way interested in changing out my calipers and/or rotors unless it was something that made sense (as in cheap availability) and retained the original lug pattern and 15 inch wheel fitment. I think someone figured out how to put Ford Ranger brakes on an Amazon without much fuss but I haven't revisited that yet.
I vaguely remember something like that. Vented Ranger discs and 240 calipers? Something like that.

I have stock 122 discs on the front of my PV, and I've noticed that calipers and rotors have gotten hard to find and spendy as hell, to the point it might be worth swapping to something else just from a cost standpoint, not even counting a performance increase.

At least the non-vented discs are immensely better than the PV's original drums. But I've still gotten them fairly hot before, makes you a bit nervous on a single-circuit brake system.
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Old 07-09-2020, 10:58 AM   #13
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I've had brake issues the whole time I've owned my 122. I have to double pump the brakes all the time. I've replaced the front calipers, master, rear wheel cylinders, pads and shoes. I've bleed it more times than I can count, and no change. I worked on a 123GT a few years back that had the same issue and I couldn't figure it out on that car either.

I'm currently in the process of collecting parts to convert it over to dual-circuit, boosted brakes, using 1800E front spindles and calipers, and a 240 1031 disc brake rear end. I'll be using the stock 1800/140 dual circuit master.
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Old 07-09-2020, 11:06 AM   #14
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Is there less pedal travel with the handbrake pulled (i.e. loose adjustment on the rear drums)?

There's not a lot different on the PV, and it has a nice firm bite more or less in the middle of pedal travel. Well, depending on how much the rear brakes need adjustment. Sometimes I cheat that a little by leaving the parking brake up a click or two as a 'faux adjustment'.
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Old 07-09-2020, 11:25 AM   #15
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Originally Posted by JohnMc View Post
Is there less pedal travel with the handbrake pulled (i.e. loose adjustment on the rear drums)?

There's not a lot different on the PV, and it has a nice firm bite more or less in the middle of pedal travel. Well, depending on how much the rear brakes need adjustment. Sometimes I cheat that a little by leaving the parking brake up a click or two as a 'faux adjustment'.
It is something in the rear. I've pulled the handbrake and it does get better, but I've adjusted the rears several times with no luck.
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Old 07-09-2020, 11:33 AM   #16
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I know the all-drum master cylinder had a sort of stopper on the opposite end of the piston return spring that was supposed to keep a modest amount of residual pressure in the system. Like 5 psi, or thereabouts. This does NOT work with discs at all, so I had to remove that when I converted. But I assume that the drums work better with it (else, why was it there). So it's usually 'good enough' with only 2 drum brakes vs 4, but it's still probably a slight issue.

On the rear I adjust them until they drag slightly, press on the brakes several times (to adjust the shoes to their new position), readjust (if needed), press on the brakes again, et.c. And leave them ever so slightly rubbing so they can self clearance into a close setting.

EDIT: I did leave out the part where I adjust them the wrong way at first because who can remember which way to pry that star adjuster???
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Old 07-09-2020, 11:37 AM   #17
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Quote:
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I have stock 122 discs on the front of my PV, and I've noticed that calipers and rotors have gotten hard to find and spendy as hell, to the point it might be worth swapping to something else just from a cost standpoint, not even counting a performance increase.

At least the non-vented discs are immensely better than the PV's original drums. But I've still gotten them fairly hot before, makes you a bit nervous on a single-circuit brake system.
Volvo OE front rotors for 122/1800 are expensive at nearly $300.00 each.

However, VP now sells their copy of the front rotor for $100.00 and they also offer new front 3 piston calipers for $150.00 each.
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Old 07-09-2020, 11:40 AM   #18
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I got their calipers (which looked a bit cruder/rougher than my originals - Chinese knockoffs?) last time. And observed the rotor prices. I didn't need rotors, but at the time thought that $600 was STEEEEEP. Nice to know they have some reasonably priced repros.
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Old 07-09-2020, 11:43 AM   #19
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Originally Posted by MikeJr. View Post
I've had brake issues the whole time I've owned my 122. I have to double pump the brakes all the time. I've replaced the front calipers, master, rear wheel cylinders, pads and shoes. I've bleed it more times than I can count, and no change. I worked on a 123GT a few years back that had the same issue and I couldn't figure it out on that car either.

I'm currently in the process of collecting parts to convert it over to dual-circuit, boosted brakes, using 1800E front spindles and calipers, and a 240 1031 disc brake rear end. I'll be using the stock 1800/140 dual circuit master.
Any chance your parking brake cables are over adjusted or are sticking or from an P1800S?

If the parking brake cables are over adjusted or sticking, the parking brake levers will hold the brake shoes away from the wheel cylinder so you have to pump the pedal to get the pistons of the wheel cylinder to start to push on the shoes.

If you are using P1800S parking brake cables, those are shorter and might be pulling on the parking brake levers.
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Old 07-09-2020, 03:00 PM   #20
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On the rear I adjust them until they drag slightly, press on the brakes several times (to adjust the shoes to their new position), readjust (if needed), press on the brakes again, et.c. And leave them ever so slightly rubbing so they can self clearance into a close setting.

I did this too. Adjusted till they dragged a little, drove it, and smoke started coming out from the rear brakes. Adjusted it out one click, no smoke, but had to double pump again at that setting.
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Old 07-09-2020, 03:03 PM   #21
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Any chance your parking brake cables are over adjusted or are sticking or from an P1800S?

If the parking brake cables are over adjusted or sticking, the parking brake levers will hold the brake shoes away from the wheel cylinder so you have to pump the pedal to get the pistons of the wheel cylinder to start to push on the shoes.

If you are using P1800S parking brake cables, those are shorter and might be pulling on the parking brake levers.
I even trying unhooking them hand brake cable and nothing changed.


For what it's worth I did try to clamp the single rear rubber brake line and when I did it had perfect pedal. That's how I knew it was something in the rear.
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Old 07-09-2020, 03:05 PM   #22
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Volvo OE front rotors for 122/1800 are expensive at nearly $300.00 each.

However, VP now sells their copy of the front rotor for $100.00 and they also offer new front 3 piston calipers for $150.00 each.
It would be nice if someone made an upgrade slotted or drilled front rotor in stock size. I too want to keep a 15" wheel, but want the best stockish braking set up possible.
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Old 07-09-2020, 03:13 PM   #23
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Thanks for all the feedback everyone. I bed in the Porterfields last night and drove the scenic route into work today, these pads are amazing! I'm 95% where I want the brakes to be, I think I will still try at least one master cylinder swap to see how I like/dislike the feel.

When I say I replaced or rebuilt every brake component on the car I mean just that. I think that these single circuit brake systems are just built around skinny tires and slower speeds and were under pressured to begin with. I have yet to drive a good Volvo dual circuit car and/or boosted system to compare but I think comparing my (much lighter) VW beetle dual circuit four drum system stops much better then the Volvo single circuit system.
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Old 07-09-2020, 03:26 PM   #24
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My wilwoods fit behind quite a few 15's as long as the barrel rib is not on the same plane as the hub face. They fit behind stock steelies with a 20 or 25mm spacer.
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Old 07-09-2020, 03:32 PM   #25
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My wilwoods fit behind quite a few 15's as long as the barrel rib is not on the same plane as the hub face. They fit behind stock steelies with a 20 or 25mm spacer.
What wildwood set up are you running? I have some of the old Avalanche Wilwood adaptor, but I didn't run them because I didn't think they'd clear a 15"

*Sorry R32 if I'm hijacking your thread a little
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