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Topic: Soft ( low ) peddle after 8.8 TC rear axle swap (Read 6005 times) previous topic - next topic

Soft ( low ) peddle after 8.8 TC rear axle swap

Ok, I have done a search and getting many answers. Here goes, I had a buddy swap in a TC rear into my 87 bird(5.0). It went pretty smooth minus a couple snags. 1st after bleeding brakes multiple times they still feel soft. He didn't swap the proportioning valve with a TC unit..Is there a difference since my PV is for drum brakes and the TC is metered for disc? Should I swap the MC next and if so what is a DIRECT swap? Last how can I get the emergency brake connected? He said its different on my car than the TC. Thanks, Ray.
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #1 –
Do you still have the factory master cyl?
1987 T-Bird TC: 5-Spd, 5-lug conv., CHE Rear CAs, '04 Cobra wheels and 13" Brakes, Vac Assist conv: '93 Cobra BB/MC & Wilwood PV, Gutted/Knived Intakes, T3 turbo, RFE6 Mani, Stinger 3" Exhaust & Oil Feed, 255HP Walbro, Kirban AFPR, RR Cam, Esslinger Cam gear and Round Tooth Conv., Gillis Boost Valve, Speedway Dual Valve Spring,  K&N, 130a 3g Alt conv., 140mph Speedo
Running Better Than Ever :burnout:

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #2 –
Quote from: Ramos617;454448
Do you still have the factory master cyl?

Yes its the factory M/C.  Ive read that changing to a 84-86 Crown Vic unit or a 93 Cobra M/C would be an improvement.
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #3 –
Yes,
With the stocker it's pushing too little fluid
Stepping up to a larger bore MC will push more fluid at the trade off of less fluid force so going too large will result in a stiff pedal

I would highly recommend tossing the stock PV valves and just get an adjustable one that way your rear bias can be tuned to your complete setup as well and handle any later brake/suspension changes
1987 T-Bird TC: 5-Spd, 5-lug conv., CHE Rear CAs, '04 Cobra wheels and 13" Brakes, Vac Assist conv: '93 Cobra BB/MC & Wilwood PV, Gutted/Knived Intakes, T3 turbo, RFE6 Mani, Stinger 3" Exhaust & Oil Feed, 255HP Walbro, Kirban AFPR, RR Cam, Esslinger Cam gear and Round Tooth Conv., Gillis Boost Valve, Speedway Dual Valve Spring,  K&N, 130a 3g Alt conv., 140mph Speedo
Running Better Than Ever :burnout:

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #4 –
Mechanic called yesterday. Axle swap is complete. There was a collapsed line causing the soft peddle. I also had '05 Mustang springs installed front and rear so kinda worried how it looks. Also he said I need a new speedometer gear , MPH are way off now with 355 gears. That's a cheap easy deal tho. Just gotta figure out which 1 to order. Thanks to everyone with tips/advice through the swap..............Next up bigger front brakes.
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #5 –
Bigger front brakes and TC brakes in the rear will require you to swap to the 93 Cobra MC.  There are several threads on here where we have discussed this as the setup on these cars is basically identical to converting over a Fox Mustang to larger brakes.  Just search "combination valve" or "cobra master cylinder" or "SN95 brakes" and it will give you a ton of reading.

http://www.foxtbirdcougarforums.com/showthread.php?36678-Need-some-advice-one-5-lug-swap-sn95-brakes-setup&highlight=combination+valve

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #6 –
Will changing the MC be enough or will I need to swap the booster as well? I have started collecting parts and have the Cobra MC on the list.
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #7 –
I want to see how the 05 springs ride height looks.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #8 –
Most folks are good with the stock booster and a 1" bore MC with the 11" front fox brakes and the TC rears. If you are going to move up to the Cobra fronts and rears (just assuming both with a five lug conversion) then you would want to move to the 93 Cobra booster. Some have gone ahead and installed the Cobra booster antiting the full upgrade at a later date with good results.

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #9 –
Quote from: Aerocoupe;454665
Most folks are good with the stock booster and a 1" bore MC with the 11" front fox brakes and the TC rears. If you are going to move up to the Cobra fronts and rears (just assuming both with a five lug conversion) then you would want to move to the 93 Cobra booster. Some have gone ahead and installed the Cobra booster antiting the full upgrade at a later date with good results.

Aerocoupe, I have collected the needed parts for upgrading the front brakes  Spindles, rotors,calipers etc. Also ordered a 93 Cobra mc and booster just to be safe. My question though is dos the adjustable PV "replace" the stock unit or is the flow still directed through it and controlled by the adjustable? Also will the 3-2 port adapter from American Muscle work( already made=less headache lol) Thanks for your input as always. Ray.
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #10 –
To see what you need to do with regards to the proportioning valve go to post #36 here:

http://www.foxtbirdcougarforums.com/showthread.php?32920-4-to-5-lug-swap/page4

As for the 3-2 kit I could not find it on American's site.  Can you post up a link to it?

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #11 –
Thanks for link on PV.... oh, after reading my post I believe the adapter is on Late Model Resto's., site...
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #12 –
If your '87 has the factory MC in it then you already have the metric threads on your brake lines like the 87-93 Mustangs and your stock MC has three ports in it like the 87-93 Mustangs.  The difference between the 93 Cobra and the 87-93 Mustangs and your Bird's MC is that it has two ports of which are metric threaded.  The 3-2 kit converts your plumbing to work like the 93 Cobra and 94+ Mustangs.  LMR sells the Maximum Motorsports kit which is $5 less on Maximum's site.  You need the following from Maximum if you have not already ordered the parts:

MMBAK-3 which is the 3-2 kit
MM-2450-A which is the plug you will need once you gut the proportioning part of the combination valve
BPV-1 which is the manual proportioning valve

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #13 –
Got my 93 Cobra booster today. Its a reman from Cardone... It looks much bigger than my old unit. Will it fit with out issues or will I need to "massage" the strut tower like some of the Mustang guys have to do to make it fit. Also got the line adapter. I now have everything to make the swap:)
87 Tbird LX w/Factory floor shifter:D   3G upgrade. Tinted Windows...85 Mustang GT steering wheel(non-cruise) 17'' Saleen SC style wheels,Front/Rear TC sway bars/poly bushings & Mustang GT steering rack...'05 Mustang V6 springs...93 Cobra MC & booster, MM adjustable C/C plates,  Work  In  Progress.......  ( On The Shelf---HO computer, 19lb injectors, HO cam, BBK headers, Explorer Intake, Cold Air Intake ,Phantom Gauges, Stinger stainless exhaust pipes )
 S O L D

Soft ( low ) peddle after 8.8 TC rear axle swap

Reply #14 –
Massaging the strut tower seems to be a car to car thing and I would blame that on the wonderful Fox Body assembly tolerances or lack of.  I have heard of guys having much better success in not dimpling the strut tower if the motor is out.

83 351W TKO'd T-Bird on the bottle


93 331 Mustang Coupe - 368 rwhp