MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

Go to Thread: PreviousNext
Go to: Forum ListMessage ListNew TopicLog In


limey222
Michael Cubbon
Portland, OR
(129 posts)

Registered:
08/01/2015 12:55PM

Main British Car:
1969 MGB GM 3.4L V6

PLEASE HELP! Front disc brakes are still locking solid after about a mile of normal driving NOW FIXED
Posted by: limey222
Date: October 03, 2015 05:28PM

I really thought I had solved this once but the car is totally undrivable, because of this still unresolved problem.

Many of you have tried to help but so far it has beaten the brightness minds on this and the MGExperience forum so this is a challenge.

This is what I done so far:

Tried Two new brake master cylinders
Moved the MS back in the pedal box with spacers to ensure free play in pedal (some suggested this)
Replaced the "shuttle" valve with reconditioned unit from UK
Replaced both front caliper assemblies (with beautifully rebuilt ones).
Flushed the system and blown-out all steel lines
Used new Castrol DOT4 fluid
Multiple bleeds

And most recently because the fault had sings of being thermal problem, insulated the steel lines and relocated them even further away from the headers.

The way the symptom occurs is that from cold start within a mile of driving at normal speeds in residential areas with stops signs the front brakes begin to drag and very quickly incrementally get worse until the car can't move.

After spending thousands of dollars and countless hour of work I can't use the car at all. PLEASE HELP!



Edited 1 time(s). Last edit at 10/06/2015 09:20AM by limey222.


limey222
Michael Cubbon
Portland, OR
(129 posts)

Registered:
08/01/2015 12:55PM

Main British Car:
1969 MGB GM 3.4L V6

Re: PLEASE HELP! Front disc brakes are still locking solid after about a mile of normal driving
Posted by: limey222
Date: October 03, 2015 07:22PM

OK, in an act of total desperation I added a second 1/8" shim between the master cylinder mounting flange and the vertical member of the pedal box. Thus means that I have pushed it back a total of 1/4" now....... and darn me if the problem seems to have been fix. When I added a 1/8" s[acer a week ago and it solved nothing I never revisited it. After all I had a good amount of pedal play before the brakes began to actuate, now I have a lot more! All I can think of is that the clevis shaft that bought new off Ebay was made too long.
I'll still be holding my breath for the next week just to be sure.


88v8
Ivor Duarte
Gloucestershire UK
(609 posts)

Registered:
02/11/2010 04:29AM

Main British Car:
1974 Land Rover Lightweight V8

Re: PLEASE HELP! Front disc brakes are still locking solid after about a mile of normal driving
Posted by: 88v8
Date: October 04, 2015 04:50AM

That's a really annoying thing to trip over.
I see Moss sell the single-circuit master with an attached clevis rod, but the dual cylinder comes bare.
Be nice to have one that's adjustable so the pedal play can be minimised.

I would guess you've fixed it now.
Fingers crossed.

Ivor


limey222
Michael Cubbon
Portland, OR
(129 posts)

Registered:
08/01/2015 12:55PM

Main British Car:
1969 MGB GM 3.4L V6

Re: PLEASE HELP! Front disc brakes are still locking solid after about a mile of normal driving
Posted by: limey222
Date: October 04, 2015 04:16PM

Still working good..that's three short trips and counting. I may actually have permanent fix. Would love to use it this afternoon to go into town, the weather is beautiful but I broke my brake light switch yesterday while troubleshooting. They are so cheaply made and fragile. Will buy yet another one and install but I'm going to look at installing a 12 volt proximity switch in its place down the road. In the meantime trying to stay out of traffic, don't want somebody rear ending me because of no brake light.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5657 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: PLEASE HELP! Front disc brakes are still locking solid after about a mile of normal driving
Posted by: BlownMGB-V8
Date: October 04, 2015 05:52PM

Proxes are available with a 10mm thread, see if you can source one with a 3/8" fine thread to match the hole in the cover. Those could become popular.

Jim


mgb260
Jim Nichols
Sequim,WA
(1917 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: PLEASE HELP! Front disc brakes are still locking solid after about a mile of normal driving
Posted by: mgb260
Date: October 06, 2015 06:25AM

There is a aftermarket street rod brake light switch. You simply drill the hole out in the cover and use a nut on each side.

[www.summitracing.com]



Edited 1 time(s). Last edit at 10/06/2015 06:36AM by mgb260.


limey222
Michael Cubbon
Portland, OR
(129 posts)

Registered:
08/01/2015 12:55PM

Main British Car:
1969 MGB GM 3.4L V6

Re: PLEASE HELP! Front disc brakes are still locking solid after about a mile of normal driving
Posted by: limey222
Date: October 06, 2015 09:19AM

I just purchased one from Napa and chased the tapped hole in the cover out with a M10-1.25 tap. It works great and is a more durable than the originals that have broken on me three times now.



Sorry, only registered users may post in this forum.