Squirrely while braking

[Rusty Muffler]

Hi, My 66 Fury has power drum brakes. It brakes fine except when I'm going 50 or more and have to brake hard. The front quickly pulls to the left and right evenly and comes to a straight stop and is startling if you don't expect it.
I've been under the car with my son and had him hold the steering wheel while I grabbed one front tire and forced it back and forth looking for looseness in the linkages but find none. I figured it might be the front brakes not being adjusted evenly so I tried that. It seems a little better but still not convinced that's the problem. Any Thoughts?
Another general question is there any tricks to get this boat to handle a little better? It's got air shocks in the rear and stock ones in front. Thanks!

 

[Davea Lux]

Part of you problem might be if your air shocks have raised the back end of the car significantly. The suspension on these cars is designed to function with the car riding level. Raising the tail up throws off the steering geometry which can adversely effect the way the car handles. There are a host of other potential causes of erratic braking: Worn out upper or lower control arm bushings, worn strut rod bushings, improper wheel alignment, improper tire pressure, Improper adjustment of the front wheel bearings, sticking wheel cylinders, contaminated brake linings, a worn pitman arm bushing, a worn or improperly adjusted steering gear or a worn idler arm. This is a lot of stuff to look at, how old are the front shocks? You might want to take the car to a good front end shop and have the alignment checked, they should do a check of the front components when they do the alignment.

Dave

 

[Rusty Muffler]

Part of you problem might be if your air shocks have raised the back end of the car significantly. The suspension on these cars is designed to function with the car riding level. Raising the tail up throws off the steering geometry which can adversely effect the way the car handles. There are a host of other potential causes of erratic braking: Worn out upper or lower control arm bushings, worn strut rod bushings, improper wheel alignment, improper tire pressure, Improper adjustment of the front wheel bearings, sticking wheel cylinders, contaminated brake linings, a worn pitman arm bushing, a worn or improperly adjusted steering gear or a worn idler arm. This is a lot of stuff to look at, how old are the front shocks? You might want to take the car to a good front end shop and have the alignment checked, they should do a check of the front components when they do the alignment.

Dave

Thanks Dave,

The air shocks are there to level the car so it doesn't sag. Your other points a good and that's probably have to do that.

 

[Davea Lux]

The car looks level enough to where I do not think that is your issue. Your probably have excessive play someplace in the front end. Car looks nice, has your teenage daughter got to drive it yet?

Dave

 

[Rusty Muffler]

Thanks Dave,
My daughter isn't old enough she's 15. She would be afraid to drive it cause it's so big. She wouldn't have liked to drive my previous car, a 67 Imperial Convertible.
I like your Chrysler's and always partial to the 64. I remember in school a guy had one and he would burn rubber for the whole block!

 

[CBODY67]

Might be the deflection of aged rubber bushings in the suspension, including the rear spring front eye bushings. Even if the wheels are receiving equal brake pressure, the bushings might not be deflecting equally and giving the impression that some mechanical looseness is in the steering or somewhere else.

Wondering if there might not be a wheel cylinder seeping a bit, but not dripping? Or if any "rust" is on the inner surfaces of the brake drums, which would be removed with additional normal use?

Handling? Run the tire pressures more toward 30psi than not. Might even try my "trick" of putting 2psi more in the front tires than the rear tires. I used to run 30/28 with good results in equal tire wear and better steering response.

The front shocks can only be "so big" to go into the tubes they work within on the K-frame. Normally 1" shock piston diameter. The difference between "std" and "hd" is in the valving. Most rear air shocks already have the 1.375" piston of non-air "hd" shocks.

Just some thoughts,
CBODY67

 

[mr. fix it]

What about brake fluid on the front brakes?
I had this on my Polara last last. the same clutching and grabbing.
I knew there was an issue but didn't find the problem until doing maintenance on the car over the winter and found the right wheel cylinder had started leaking but just enough to coat the shoes on the right drum

 

[Big_John]

I would look at excessive wear in the front end components (as already mentioned) and/or front end alignment.

 

[1978 NYB]

If I understand your problem is the car pulling sharp to the left or right when braking at 50 mph?

Replace both front brake hoses.

 

[70bigblockdodge]

Barring a brake not working properly or gross misadjustment ( left and right pull kind of rules this out). You alignment would be suspect if you recently worked the front suspension or bad impact. I have to agree with bushings, most likely the lower control arm bushings, this will make it handle poorly also.

 

[bluefury361]

Lots of good advise here. I might add, try adjusting the rear brakes. Might be to much bias on the front. Inspect the front and rear shoes for signs of contamination, (grease, brake fluid etc). If not done already replace all three flex brake hoses.
Lose the air shocks. If there's a sag then replace the leaf springs. Shocks are not meant to support weight, that's the springs job. The top rear shock mount/cross member can be damaged if over loaded.
Beautiful Fury. Good luck.
Will.

 

[mrfury68]

I would have to say check your front suspension if you have gone over your front brake system. Has the front end bushings & hardware ever been replaced? If not, being 52 years old it is safe to say the rubber is probably dry, hard & possibly cracking. When I rebuilt my front end about 10 years ago it amazed me what a difference it made in the ride, handling & stopping of my Fury. That is a great looking 66 you have. Cool Pontiac too.

 

[Rusty Muffler]

Thank you all for your replies and compliments. Yes the front control arm bushings are old and cracked. Looks like I'll have to have a trusted front end person look it over.

Just to be clear, she stops straight, but just in the beginning of a hard stop the front warbles a little before stopping normally. The brakes are dry and shoes are in great condition. They were manual but I switched over to the factory brake booster years ago.

 

[Rusty Muffler]

I suppose if one front brake was braking first before the other it would cause that? I'll try re-adjusting the front brakes to try and even them up.

 

[78Brougham]

Make sure they aren't glazed also. Or one is and one isn't.