73stroked duster
Well-Known Member
Looking to improve braking power on my 73 duster. Will changing the stock single piston caliper to a wilwood 4 piston caliper setup help?
Have disk up front drums in back no power buster. Just installed new master cylinder with a 1.031 bore. Have a 360 stroked motor. Car does stop but ok with a Good amount of pedal pressure.I agree. Only thing I'd add would be to insure the system is working well. Check that the pistons and calipers move smoothly, fluid isn't too old, and the drums are also adjusted and working well. If the fluid comes out the bleed all brownish, then bleed all four corners good.
As far as pads (and shoes) go. If they were produced by a participating member of the friction manufacturer's association, there will be a lining code on the pad. You can use the last two letters as a rough guide to effectiveness of the material. (or they will be positioned as shown in the link for the newest revision of the edge lining code).
Of the big companies, Centric did not particpate, but you can e-mail them. Smaller specialty companies generally don't mark them either.
Do you think larger rotors and calipers will make a differencegoing down to a 15/16" bore would reduce the pedal pressure needed for a stop but increase the travel on the brake pedal.
Depending on your vacuum a standard booster won't work well.
In my case, I have a hydratech hydroboost (and a matching 1 1/8 master cylinder since it boosts so much), which runs off the power steering pump. That alone makes a huge difference.
Do you think larger rotors and calipers will make a difference
Do you think larger rotors and calipers will make a difference
I will check the banacing valve. Since I installed the new master cylinder and bleed the brakes I can’t get the luminated brake light to go off unles I remove the wire from the valve.If pedal pressure is the only issue a 15/16” master cylinder is the way to go for manual brakes. Otherwise some kind of booster is in order, depending on your vacuum levels.
If stopping power is an issue, you probably have something wrong with your brakes. The stock 73+ disks and drums actually work pretty well if they’re in good shape. Make sure the pads/shoes aren’t contaminated, the drums are properly adjusted, and the factory combination valve is balancing the braking front to rear (it can get out of whack if the brakes are bled improperly).
I would make sure everything is working properly first. If you have 15” rims, you can buy a set of 11.75” caliper brackets and run the later Mopar 11.75” rotors, they came on some of the 77-81 B/R bodies. You can order the brackets from DoctorDiff. Also, if you actually have A-body calipers, you can use the later FJM body calipers. Externally they’re the same, but they have a larger piston bore than the A body calipers. Both those and the A body calipers will work with the 11.75 caliper brackets.
If you’ve got 14” rims you’re stuck without a rim upgrade. And if you’ve got 15” rims the 11.75’s are about as big as you can go.
I will check the banacing valve. Since I installed the new master cylinder and bleed the brakes I can’t get the luminated brake light to go off unles I remove the wire from the valve.
I will check the banacing valve. Since I installed the new master cylinder and bleed the brakes I can’t get the luminated brake light to go off unles I remove the wire from the valve.
I’m assuming so this is the way I got it.Is this some kind of brake kit? Because that’s not a stock valve.
I’m assuming so this is the way I got it.
Thanks for all the reply’s. I just bleed all the brakes again and all brakes seem to be locking up good. I have a pretty firm pedal but the light is still on. Thinking about replacing the valve and see what that does. Getting tired of bleeding though.Ok. Well, thing is we don't even know what brakes you have on there now. Because that's not a stock valve.
I was assuming, and based on the comments I would say most of us have been assuming, that you had stock 73+ disk brakes because you asked about stock brakes. Since that isn't a stock valve, we really don't have any idea what you have. So, until you know what brakes you actually have, I don't know how much help anyone can really be.
The light would still indicate an issue with your current system though, and that still needs to be sorted out before you go any further.
Maybe this will helpI don't recognize the valve either, but I'm most familiar with the earlier fixed caliper systems.
Would the previous owner know? If you have some additional photos, maybe someone will recognize it. Might also look at Master Power Brake, SSBC and other aftermarket places.
If the PO doesn't know, and there is no markings, knowing where the connections from the m/c go, and what lines go in and out of that valve we can figure out what is going on.
My suggestion is to make a simple drawing of where the tubing from the cylinder goes, noting all the junctions and devices on the way to each brake. That's just me, I can understand things better with diagrams.
To learn about the braking hydraulics, the 1967 pamphlet is good start. In this they introduce the tandem master cylinders. All routing from then on is just minor variations on that. (for chrysler and most american cars that is). The newer booklets I linked to assumed that background was familiar.
1967 Imperial & Chrysler Dual Hydraulic Brake Repair Book - Session 232
Correct light problem after I installed m/c. I have read that I should have used a proportional valve centering tool when bleeding brakes.Im not sure how to recenter the valve after the fact even if you can. Maybe I need to just install a new oneRealize I should clarify that its unlikely the proportioning relates to your pedal feel issue as you've described it. If its working right, it won't start proportioning until something like 500 psi is reached. So when you start to push on the pedal, all four corners will get the same pressure.
The rears help most when you first apply the brakes, so do make sure they are adjusted etc.
One last thought, the brake warning light is also wired to a switch on the hand brake. Its possible there's a wiring or switch issue. The only thing that has me wondering about all of this is that it sounds like the problems started with the installation of the new m/c.
What!?Correct light problem after I installed m/c. I have read that I should have used a proportional valve centering tool when bleeding brakes.Im not sure how to recenter the valve after the fact even if you can.