Brake master cylinder upgrade?

Topic: Brake master cylinder upgrade? (Read 19566 times) previous topic - next topic

Brake master cylinder upgrade?

April 07, 2011, 12:37:56 PM

I recently upgraded my 86 Cougar to 87 TC front brakes and an 8.8 disc rear end. I test drove it with the original master cylinder and the brakes feel horrible. You have to push them almost to the floor to get it to stop and the pedal feels very soft. The brakes have been bled and all air appears to be out of the lines.

I am planning on upgrading the master cylinder but would like to know what everybody who has done similar brake upgrades is using. Is the 84/86 Crown Vic master cylinder referred to in the Cool Cats tech pages a direct swap? I am also hoping to swap to the TC proportioning valve at the same time.

Any info you can share is appreciated!

Brake master cylinder upgrade?

Reply #1 – April 07, 2011, 03:02:07 PM

I;ve heard the Cobra MC and gutting the stock prop valve or getting an aftermarket adjustable is a good way to go...in reality, I haven't put it into practice, so take my words with a grain of salt lol

Brake master cylinder upgrade?

Reply #2 – April 08, 2011, 03:03:03 PM

From what I can tell you want an MC with a 1" bore. I am pretty sure the 83-86's have a 2 port SAE threaded MC. The '85 Lincoln Towncar also uses a 2 port SAE threaded MC with a 1" bore which is about the best unit for most all brake upgrades. The 93 Cobra MC is the one to use if the brake fittings are metric and it also has a 1" bore. Hopefully I am correct on the 83-86 cars as the 93 Cobra unit is PRICEY!!!

You may just want to gut the front side of the stock proportioning valve and using a manual proportioning valve. This requires the cap or nut on the front of the stock PV to be removed and the spring and plunger are removed and discarded. Install the new cap (be sure to put the o-ring on it) and that part is down. Next you will need to find a location in the brake line going to the rear brakes from the stock PV and install the manual proportioning valve. It can be some work but you are now able to dial in the rear bias and it sure does make a difference. Here is a picture of the stock PV:

Here is the manual proportioning valve:

http://www.summitracing.com/parts/WIL-260-8419/

Here is the plug you will need to replace the one on the original combination valve:

http://www.maximummotorsports.com/store/index.php?main_page=product_info&cPath=49_145&products_id=1411

Darren

Brake master cylinder upgrade?

Reply #3 – April 08, 2011, 04:41:08 PM

I went with a 87 Mustang booster and master with the mustang PV and it has a soft pedal. But big but here (lol He said big but) I had a hard time getting fluid at the rears when I bleed the setup I got a re-maned MC and I think it was junk out of the box? But If I had the doe Id go with the cobra MC I'm gonna try to warranty the one I got and if it still suck Ill come back here and see what you did?

Brake master cylinder upgrade?

Reply #4 – April 08, 2011, 04:48:36 PM

Thanks for the info guys! The 86 does use the old cast iron type, so I probably can't use the newer plastic style without some replumbing, which I would like to avoid. The 85 Town Car unit mentioned by Aerocoupe is only $15 (remanned) at Autozone, so I might as well give it a try. I'll have to use the stock TC proportioning valve right now, as I can't afford an aftermarket one. Hopefully it works well enough.

Brake master cylinder upgrade?

Reply #5 – April 08, 2011, 04:51:47 PM

Good luck

Brake master cylinder upgrade?

Reply #6 – April 08, 2011, 07:48:14 PM

Quote from: Loaded87IROC;357527

Thanks for the info guys! The 86 does use the old cast iron type, so I probably can't use the newer plastic style without some replumbing, which I would like to avoid. The 85 Town Car unit mentioned by Aerocoupe is only $15 (remanned) at Autozone, so I might as well give it a try. I'll have to use the stock TC proportioning valve right now, as I can't afford an aftermarket one. Hopefully it works well enough.

Maximum Motorsports sells adapter kits..... http://www.maximummotorsports.com/store/index.php?main_page=index&cPath=49_140

Brake master cylinder upgrade?

Reply #7 – April 09, 2011, 01:00:05 AM

I would think that the stock TC PV will be fine. The only thing I am not sure about is how different the boost by the Teeves system will compare to that of the stock T-Bird vacuum booster and Lincoln MC. If you feel that the pedal is hard then the next step would be to use the 93 Cobra booster.

Darren

Brake master cylinder upgrade?

Reply #8 – December 07, 2011, 11:03:46 AM

Quote from: Loaded87IROC;357527

Thanks for the info guys! The 86 does use the old cast iron type, so I probably can't use the newer plastic style without some replumbing, which I would like to avoid. The 85 Town Car unit mentioned by Aerocoupe is only $15 (remanned) at Autozone, so I might as well give it a try. I'll have to use the stock TC proportioning valve right now, as I can't afford an aftermarket one. Hopefully it works well enough.

Any update? I am in the middle of this also.

Brake master cylinder upgrade?

Reply #9 – December 07, 2011, 03:30:08 PM

I used a cobra m/c and actually found the pedal too hard. I've heard of people using 95/6 v6 mustang units as well

Brake master cylinder upgrade?

Reply #10 – December 07, 2011, 08:22:32 PM

I haven't done anything about the brakes. I bled them again very thoroughly and the brake pedal feels much better now. I am still using the original MC and proportioning valve. Braking is good although I am sure it could be improved. I don't drive aggressively but have had to make a couple of sudden stops and didn't have a problem. I still plan to swap the MC and prop valve but it will probably be a few months.

Brake master cylinder upgrade?

Reply #11 – December 07, 2011, 08:40:50 PM

I didn't go to disc in the rear, but did the bigger brake upgrade using 88 mustang spindle/rotor and upgraded to 73mm calipers. I had a 84 TC in the yard and used the MC from it as well as the guts from the 88 mustang PV and the booster. So far so good. The beauty of the TC MC is that it's a straight bolt on.

EDIT: I just realized that TC can mean Turbo Coupe OR Town Car....I was referring to Town Car. Sorry for the confusion.

Brake master cylinder upgrade?

Reply #12 – December 07, 2011, 09:53:17 PM

Aero

Brake master cylinder upgrade?

Reply #13 – December 09, 2011, 09:00:00 PM

What everyone needs to realize is that the 85 Lincoln MC is a direct bolt in. All of the threads are SAE and not metric like the 94-95 Mustang MC. I have the 94-95 MC on both my cars and had to build brake lines to make them work. I also used the 94-95 vacuum boosters in both cars. I wish I would have used the 93 Cobra vacuum booster as it would have been a more direct bolt in. Please realize that I have full Cobra spec brakes on both cars so what I am using booster wise is for that setup as well as gutting the PV side of the stock valve. I use an external adjustable PV so that I can tune the rear brakes to the front brakes. Even a change in brake pad compounds will benefit from bedding the new pads even if the rotors are seasoned (read used) and then readjusting the PV to compensate for the different brake pads.

There is no one MC, Booster, PV setting that works for every setup.

Darren

Brake master cylinder upgrade?

Reply #14 – December 09, 2011, 09:22:51 PM

I have changed my setup since my last post here and upgraded to the 93 cobra master and gt booster. The fittings were different but I was able to use bubble to flair adapters. I'm still running T.C stock brakes with a gutted stock PV with an adjustable wilwood pv. The pedal is firm real firm, I like it I'm 6'5'and 325 lbs and don't have a problem applying the needed pressure.I have almost every thing for the 5 lug and cobra brake upgrade. I am told that with the upgrade I may get a little softer pedal
I guess due to the dual piston caliper. If I get a soft pedal I will try the 93 cobra booster for the ease of swapping to the same holes.