Brake Lock Up

[RDKeysor]

My '60 BN7 has now had brake lock up on three occasions, most recently on Saturday as I transited through World Golf Village on my way to our annual Jacksonville, FL, area Brit car show near St. Augustine. I was motoring along when an SUV made a left turn right in front of me. I hit the brakes, making a goodly screech and leaving black stripes on the road. The car also started to torque counterclockwise as it skidded. This car was rebuilt about seven years ago, then purchased by me from a rather disinterested PO. It has what look like new brakes, the drums and front brakes. After a less noisy lock up earlier, I had backed off the right rear drum one notch. The car has tires I believe were made in 2005, 165X15, made by Bridgestone, according to the code. I have purchased a brake servo kit from Victoria British for this car, which was not originally so equipped, and am now reluctant to install it. To give you an idea how this experience got to me, on the way home I rolled through caution light that came on late, reluctant to brake hard and induce a skid. I've driven my Porsche 968 daily driverfor 15 years (it does have ABS) and never put it into a skid. I'm puzzled.

 

[AH100M]

You need to go through the brake adjustment procedure, as per the manual, for each wheel. If one or more of them can't be adjusted properly then we'll have something to go on. Unless all of the brakes start off in the proper state unbalanced braking can be expected. It's not hard to do but critical.

On my 100 I had a front brake I couldn't stop from locking up. I changed everything on that side - hose, pipes, drum, cylinders; nothing worked. I finally determined that I had defective linings. New linings weren't available at the time so I swapped out the front brakes and mounted discs!

 

[Andy65]

65 BJ8. Just the other day, my left rear locked up while dragging the brakes going slowly down a steep driveway. Stomping and releasing the pedal quickly a couple times released the brake. My guess is either the cylinder stuck, rust on the drum prevented the shoe from releasing or when the hand brake was released, the shoe didn't pull away. Possibly putting the handbrake lever down and immediately backing up was a contributing factor in the shoe sticking to the drum.

 

[Randy Forbes]

I'd ditch the ten (<10) year old tires first. Rubber NEVER stops curing once it's removed from the mold, it just keeps getting harder and harder.

As for the brakes, I'm assuming it's the rear (drum) brakes that are locking. Is it BOTH sides, or just one? I've found that when only one side locks up, that brake is usually functioning just fine, but the opposite side (in at least a couple of cases) is not working, due to being soaked in axle lube from a failed hub seal.

After only approximately ten (>10) years of use, I just had to replaced my brake hoses (swollen shut) shoes (LH soaked in oil) rwc seals (might as well...). Even though the car was "rebuilt seven years ago," that's No Guarantee that the brakes don't need to be gone through again. Ask anyone that drove a Healey when it was just a car, and even though the mileages would be higher, you NEVER got away with going 7 to 10 years without a brake job

 

[DerekJ]

A leaking brake cylinder means fluid can get on the drum and will cause the shoes to stick to the drum. If your car 'torqued' then only one brake was stuck and this could be the cause.

 

[RDKeysor]

I had the car in question on jack stands today, and there is no hint of oil or brake fluid leaking down onto the rims. I agree that old ties tend to get harder, but I must say they sure scrubbed off a lot of rubber when I went into a skid. Years ago I had a quartet of what were probably old Yokohama tires on my Porsche 968 and had just switched them onto the car when I went for a drive on damp streets. I had the rear end break loose just a tad on consecutive turns, something i have never had happen before or since in 14 years with this car. I went home removed the wheel and replaced the tires. The tread was there, but the grip was gone.

 

[bob hughes]

FWIW

I think that you are going to have to get your hands dirty and strip the rears down and get those drums off.
Inspect all the parts for contamination and see how the brake cylinders are performing - have someone press the brake peddle gently whilst you observe the cylinder action on each side.



Bob

 

[RDKeysor]

At the suggestion of a friend, I bled the left rear brake and saw a few air bubbles emerge with the fluid. I then did a little road test at relatively low speed, with all four wheels seeming to lock up with a vigorous brake application. Previously it seemed that the right rear was grabbing but not the left, tending to torque the car around counter clockwise. I'm amazed how easy it is to really scrub off the tires on this car, an experience that includes the smell of burning rubber. This suggests to me that these relatively old tires (2005) are still soft enough to take quite a bite under braking. I'm sure that I don't have any leaking fluid inside the drums. One wonders what will happen if I put the recently purchsed servo on the car---my car was not offered with a brake servo. As an aside, one of our club members came up with a homeless but functioning 3000 tachometer to replace the BN6 unit that came in my car. I knew this because the red line on my car's tach was at 4800 rather than 5200 (think those are the correct numbers). One less issue that I won't have to address in the future.

 

[GregW]

I'm amazed how easy it is to really scrub off the tires on this car, an experience that includes the smell of burning rubber. This suggests to me that these relatively old tires (2005) are still soft enough to take quite a bite under braking.

I wasn't there, but old hard tires will still loose material. They aren't as hard as the road so they loose the abrasion fight.

I had the car in question on jack stands today, and there is no hint of oil or brake fluid leaking down onto the rims.

I'm sure that I don't have any leaking fluid inside the drums.

Until you look inside, how can you be sure?
Sorry if I sound harsh, but you seem to be convincing yourself things are OK when your car looses control.

 

[DerekJ]

The tyres are 9 years old and need to be changed.

 

[bdcvg]

Personally I believe upgrading to the servo is only going to make lockup worse. I am converting to no servo and smaller master cylinder plus braided lines which I believe will provide more pedal control.

 

[Andy65]

Clue here is you added a brake servo. I seem to recall something like a check valve and filter in the servo. Clean and check?

 

[RDKeysor]

I'm only reluctant to purchase new tires because my car running 60-spoke wheels and inner tubes provides an almost flawless ride at all speeds. No lumpiness, cowl shake or wandering. I'm contemplating the Nexen tires that many extol here, but I'm not sure about getting them mounted. We do have an independent tire show in Jacksonville that has mounted and dismounted tires for my since sold Jag and for my BN6, most recently so I could replace three broken spokes. I am almost convinced that the tires are the issue, as I don't really think it's the brakes.

 

[John Turney]

I used to have tires that were much older than yours. I had no brake lock up. The only times that I've had it was when the linings got wet with fluid (not in the Healey).

 

[Deleted member 8987]

Ah. The tyres that came on the Jag were old....beautiful tread...but the sides were so badly cracked you could see the air inside.
I finally changed them.
However, I have a set of 15" 2-1/4" wide whites stored for my old Ford...Bias ply and all....just for if I decide to put them on spare rims for shows.
I'd drive on them...just not on the freeway.

 

[DerekJ]

I'm confused by your logic. You believe it is the tyres, the tyres are 10 years old anyway, but you don't want to change them. That doesn't seem to add up. Take off the rear drums and check there is no brake fluid on the shoes. If the car torqued to one side that is a very likely cause.

 

[steveg]

I'm confused by your logic. You believe it is the tyres, the tyres are 10 years old anyway, but you don't want to change them. That doesn't seem to add up. Take off the rear drums and check there is no brake fluid on the shoes. If the car torqued to one side that is a very likely cause.

I agree with Derek on the logic thing. IMHO the tires(tyres) here are a distraction from the real issue which is the state of the rear brakes: has brake fluid or axle oil leaked onto the shoes?

I just replaced 2002 Vredesteins that looked and acted normal in every way, with no special lockup properties. If they're all the same age, why would that favor the rears only?

 

[Michael Oritt]

After you get your brake issue resolved you had best address getting tires as yours are certainly out of date and living on borrowed time. If you do not have someone in Jacksonville to mount tires and repair the wheels check out Hendrix Wire Wheel in Greensboro NC. Allen Hendrix is a great and reliable person and has much specific Healey knowledge. He recently mounted a suit of Michelin XAS 180-15 tires to my 60-spoke Daytons. I simply shipped him the wheels, had the tires drop-shipped to him from Coker and a week or so later everything came back to me trued, mounted and balanced.