Panic Stop - Great Scott what just happened!

Do you know when the rear wheel cylinders were last replaced? Have you noticed any brake fluid dripping from a drum? Maybe pull the drums off and check that the shoes on both sides are dry? How old are the front calipers? Do you know when the brake fluid was last changed?

ALB posted:

Do you know when the rear wheel cylinders were last replaced? Have you noticed any brake fluid dripping from a drum? Maybe pull the drums off and check that the shoes on both sides are dry? How old are the front calipers? Do you know when the brake fluid was last changed?

Al,

The car is less than two years old and has been driven less than 2800 miles.  The brakes are not leaking and the new tires were installed less than 200 miles ago. 

Maybe the brakes on 1 rear wheel need to be adjusted?

I would get a trusted car guy friend and take a quick trip to a long stretch of empty road or a vacant t parking lot for some brake testing. Have your friend record or watch your wheels as you get up to speed and do a controlled "panic stop". Do this several times while he watches each side of the car. It sounds like the rears are locking up and the fronts aren't engaging enough. And as Al said one rear side, the side that tried to pass, is engaging with more force than the other.

You'll get a much better idea of what's happening which will give you a better diagnosis and a better plan for fixing the problem. We've had some on here with similar brake problems and one had an issue with one brake engaging too much and another with one brake that was sticking and not engaging at all. You'll need to figure out which problem you have.

With only 2,800 miles on the clock you haven't even gotten it "sorted out". There was no road testing done when the car was finished so now you're the one left to get all of these persnickety little safety issues, like properly working brakes, figured out.

Be careful but get it done.

I'm not saying it isn't the brakes as it might be. There might be a small leak in one wheel cylinder leaking just a touch of brake fluid on a drum, that would do it for sure. And you wouldn't see it outside the drum necessarily.

I'd also have an alignment done, if one rear wheel or both are toed out that would definitely cause this. You want zero rear toe or very slight toe-in. If your steering wheel was anything but perfectly straight ahead that could cause this also.

No proportioning valve ?

You'll have to remove the rear drums to find issue.  It could be slight fluid leak (brake cyl or axle seal), mis-adjusted shoes, glazed drum/shoes, loose shoe connector, etc.  I assume VS replaces all the rubber brake lines - but I still prefer the stainless steel braid covered lines as they don't balloon when under pressure (or fail by compressing and squeezing off fluid).  If you haven't driven it much this year the rotors and drums will get a slight rust coating which will wear off after a bit of driving.

I'm actually surprised the front discs did lock up first.  Although with such low weight there it wouldn't have been a handling issue.

WOLFGANG posted:

You'll have to remove the rear drums to find issue.  It could be slight fluid leak (brake cyl or axle seal), mis-adjusted shoes, glazed drum/shoes, loose shoe connector, etc.  I assume VS replaces all the rubber brake lines - but I still prefer the stainless steel braid covered lines as they don't balloon when under pressure (or fail by compressing and squeezing off fluid).  If you haven't driven it much this year the rotors and drums will get a slight rust coating which will wear off after a bit of driving.

I'm actually surprised the front discs did lock up first.  Although with such low weight there it wouldn't have been a handling issue.

He said the rears locked up but he didn't say anything about the fronts locking up or even engaging.

I had just the opposite.  My fronts locked and the rears did not.  We know how that turned out.

Lane that was a real tragedy for you and your car.... 

I find, the fronts lock up quite easily, especially on a bumpy road when you try to stop quickly.   I am not sure how that could be fixed when you consider the limited amount of weigh these cars have and the great rear weigh bias that is a pendulum waiting to swing forward given the chance. 

Pretty important on these cars to buy a very soft tire compound, sport rated, to give you the maximum amount of grip in a bad situation. 

I meant to type surpized the front didN'T lock up - defective mind control of keyboard

IaM-Ray posted:

 I find, the fronts lock up quite easily, especially on a bumpy road when you try to stop quickly.   I am not sure how that could be fixed when you consider the limited amount of weigh these cars have and the great rear weigh bias that is a pendulum waiting to swing forward given the chance. 

What size tire do you have on it? What rear brakes does the car have on it? Throw 40 or 50 lbs. in the frunk and then see how it reacts. 

The front brakes (factory Karrman Ghia discs, 4 1/2" rims with 135's- evil little pieces of rubber!) on my Cal Look Beetle would lock up if I wasn't careful; with wet or dusty pavement it was even worse. Increased braking power in the back helped balance it out. Al 

Seems to me that it might have been one of the fronts that locked up.  If your fronts were not locked and it was just the rears that were locked, it seems like that would just cause you to drag the rear end, not make it come around.

If the fronts lock, it will "push" and not turn, if the rears lock it will swap ends. You may have air in the lines or the master cylinder may be bad. I would bleed the brakes, and try a slow speed, 15-20mph panic stop on the dirt to see which wheels lock up. Ideally all of them should lock up at the same time. I have AC Industries  5 lug disks on the front and I can lock the fronts up at will. I'm guessing your master cylinder is not up to the task.  Also, wheel alignment and rear brake adjustment can steer you where you don't want to go in a panic stop!

aircooled posted:

No proportioning valve ?

This^ There are only a couple of things (all mentioned) that can cause this. You just need to get to the bottom of it and fix it.

I had a similar issue and discovered the previous owner had the master plumbed wrong (left to right instead of front to back) and was a near disaster when I discovered it.

I had the rear lock up on me once and did a full 180

OK, if you say so.  It just doesn't seem logical to me. Front wheels still spinning and rear wheels just dragging.  Can someone explain the physics of that? 

I've taking the car to a company here in Charlotte that specializes in foreign cars of all makes, models and from all eras. 

Have also sent them a photo copy of all the ideas those members of this forum have been so kind to give as to what they think the problem might be. 

If any one else is willing, I would be very grateful if you too will post your idea as to what you thing the problem might be which I will also forward to them.

Kind regards to everyone for your help,

Cliff