Author Topic: 66 GT Mustang Brakes  (Read 1463 times)

Offline Tiny

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66 GT Mustang Brakes
« on: April 15, 2017, 05:15:23 AM »
Hi all, as the 66 GT does not have power assist how well should the brakes function.  I have a good pedal and front and back Discs and Drums are working okay.  It just doesnt seem to stop real good or give you confidence in braking.  I know I should expect too much being non power assist but it doesnt seem as good as it should.

Any hints?

cheers
67 San Jose Built GTA 390 Coupe
C6, PS, A/C

Offline carlite65

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Re: 66 GT Mustang Brakes
« Reply #1 on: April 15, 2017, 08:34:30 AM »
what brand of brake shoes/pads are you using? they can make a difference.
5F09C331248

Offline sgl66

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Re: 66 GT Mustang Brakes
« Reply #2 on: April 15, 2017, 01:54:59 PM »
Several things could be causing issues including stuck pistons in front calipers, proportionong valve with too much rear bias, bad pads/shoes or front rubber hoses delaminated internally which clogs the hose and prevents fluid getting to the caliper. When everything is working correctly, the brake system works fine.
66 GT 6T09K12---- scheduled Oct 14, bucked Oct 13 '65

Offline mjd 65

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Re: 66 GT Mustang Brakes
« Reply #3 on: April 15, 2017, 03:21:33 PM »
Once you get used to modern power-assisted, floating caliper anti-lock brakes, going back to 60s era manual four piston disc brakes can be an interesting experience, even when everything works correctly.  The four piston discs have good stopping power with semi-metallic pads, but, as Hertz warned Shelby drivers, you should be prepared for some extra pedal effort.

Mel
July 65 silver blue Metuchen hardtop

Offline Bob Gaines

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Re: 66 GT Mustang Brakes
« Reply #4 on: April 15, 2017, 05:19:19 PM »
Hi all, as the 66 GT does not have power assist how well should the brakes function.  I have a good pedal and front and back Discs and Drums are working okay.  It just doesnt seem to stop real good or give you confidence in braking.  I know I should expect too much being non power assist but it doesnt seem as good as it should.

Any hints?

cheers
I have heard this more times then i can remember. The 65 and 66 cars do not brake as good as many modern cars first off. If you don't have a frame of reference it is hard to distinguish in words if you do not have a properly functioning brake system or it is just you are having higher expectations then a properly functioning 50 year old technology system can provide. Just some thoughts for the discussion.   
Bob Gaines,Shelby enthusiast, Shelby collector , Shelby concours judge SAAC,MCA,Mid America Shelby

Offline Tiny

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Re: 66 GT Mustang Brakes
« Reply #5 on: April 16, 2017, 02:15:30 AM »
Thanks for the reply guys.  I'm trying to maintain originality so hence I'm shying away from updating.  I'll recheck all of the pistons and hoses.  I a have put in brand new disc pads on the front from the mustang store so they may need a little bedding in.  I havnt been able to take it for a good run as it is not registered as yet so I'm just back and forward in the driveway.

Is there a way to check if the proportioning valve is working correctly?

cheers
67 San Jose Built GTA 390 Coupe
C6, PS, A/C

Offline sgl66

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Re: 66 GT Mustang Brakes
« Reply #6 on: April 16, 2017, 06:08:09 PM »
Thanks for the reply guys.  I'm trying to maintain originality so hence I'm shying away from updating.  I'll recheck all of the pistons and hoses.  I a have put in brand new disc pads on the front from the mustang store so they may need a little bedding in.  I havnt been able to take it for a good run as it is not registered as yet so I'm just back and forward in the driveway.

Is there a way to check if the proportioning valve is working correctly?

cheers
A rule of thumb on rebuilt prop valves is to have 12 (I think) threads exposed. After that it's fine tuning....if the rears lock up, you went too far. If you have a flat grassy area, you can run the car in there and slam the brakes on to see which wheels lock up first.
66 GT 6T09K12---- scheduled Oct 14, bucked Oct 13 '65