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-   -   Questions, before I balk about brake and alignment work... (http://forums.pelicanparts.com/porsche-911-technical-forum/741352-questions-before-i-balk-about-brake-alignment-work.html)

Tremelune 03-27-2013 01:19 PM

Questions, before I balk about brake and alignment work...
 
I just had four new tires installed (stock size on stock wheels) with a four-wheel alignment performed by a well-regarded Porsche race shop. I also had two rebuilt front calipers installed with new rubber lines and a full flush of the clutch and brakes.

The clutch feels great. The brakes are strong enough to lock up the wheels when you get on them. The car is dead smooth at speed and seems to handle quite well.

My issues are this:

- The steering wheel is now cocked slightly left (maybe 1 degree) while driving straight, on different kinds of roads.
- The brake pedal feels softer than it did with a frozen caliper and doesn't engage for an inch or two.

My plan is to drive the car a few hundred miles to see if things settle and shake out, but I'm disappointed. I expected the car to be returned to me tracking perfectly straight with very firm brakes. My experience is limited with these cars. Should I expect a change over time with the same pads and rotors or is this the best pressure I'm going to get? Is it unreasonable to expect a straight steering wheel from an alignment that is within OEM on an '87 Carrera??

I realize it's an old car, and I know these brakes are difficult to bleed, but I would have expected guys who race these things on weekends to know how brakes should feel. I would also have expected someone who just did an alignment to look at the steering wheel and say "oh crap this isn't straight" when they drove it.


Alignment specs, for your perusal/critique:

http://ensaster.com/pics/pelican/alignment.png

timmy2 03-27-2013 01:28 PM

Take it back and tell them to do it right.

plumb4u2 03-27-2013 01:38 PM

Quote:

Originally Posted by timmy2 (Post 7354198)
Take it back and tell them to do it right.

agreed...If these guys are professional you need to take it back now, do not put couple hundred miles on it then take it back that just makes no sense

spuggy 03-27-2013 03:13 PM

Quote:

Originally Posted by Tremelune (Post 7354187)
- The brake pedal feels softer than it did with a frozen caliper and doesn't engage for an inch or two.

The brake pedal is supposed to move before the brakes bite. There is an adjustment so you can move the pedal up or down slightly - but there should always be free movement.

And, not being snarky - but isn't that how 3.2 brakes normally feel?

I had (reconditioned) 3.2 brakes fitted by the PO on the car for 30,000 miles - your description exactly matches how they felt until I replaced them with 996 N/A brakes...

Tremelune 03-27-2013 03:25 PM

Quote:

Originally Posted by spuggy (Post 7354373)
And, not being snarky - but isn't that how 3.2 brakes normally feel?

I honestly don't know. My nearest comparison is the brakes on an E30 M3 and a 993, both of which feel significantly better. My real indicator is that they felt better before being bled.

porschenut 03-27-2013 04:20 PM

Quote:

Originally Posted by spuggy (Post 7354373)
but isn't that how 3.2 brakes normally feel?

Absolutely not. The brake pedal should have maybe a half inch of free play, then be firm. There should be no spongy feel at all. A firm brake pedal after brake fluid change should be an easy matter on any 911.

BernieP 03-27-2013 05:15 PM

Every time I have rebuilt calipers it took a short while for the pedal to get firm at the top of it's travel. I s told that the new seals pull the pads back a we bit for a short time till every thing beds in.

Bernie P

rusnak 03-27-2013 10:14 PM

Zero front camber? A lot of front toe in there.

And it sounds like your brake pistons might be retracted too far. The brake pedal should not be spongy. I'm sort of curious as to what the conversation was with the race shop prior to beginning the work.

Joe Bob 03-27-2013 10:37 PM

If it doesn't feel right, take it back and ask the provider......ya doan wank about it on the net....just sayin'.....

DRACO A5OG 03-27-2013 11:48 PM

your alignment readings are way off. get them in the car and show them. if they just bandaid it with toe adjust, demand your money back and find a real alignment shop

caster up front should be even.

my specs personally is for agressive street and some de, -0.75 front camber each side and -1.50 rears. toe zero up fromt -1/16 total in rear and corner balanced, did it myself with string, borrowed the scales. it is very time-consuming but doable.

bkreigsr 03-28-2013 04:33 AM

I was just going to compliment you on your excellent alignment results.
The specs are all almost dead center of the suggested range, and pretty even side-to-side.
You realize the settings are for street driving -right?
You should have no problem getting them to re-clock the steering wheel, as they left a note on the bottom of the sheet that the wheel was even when they started.
Brake situation sounds normal - you mention nothing about spongeness - only that it takes an inch or so before it bites - that's different than the sponge thing.
Bill K

Rot 911 03-28-2013 05:50 AM

Quote:

Originally Posted by porschenut (Post 7354507)
Absolutely not. The brake pedal should have maybe a half inch of free play, then be firm. There should be no spongy feel at all. A firm brake pedal after brake fluid change should be an easy matter on any 911.

I agree. I do my own work and my brakes feel, as a fellow Pelican onec stated, "like the hand of God is slowing the car down."

group911@aol.co 03-28-2013 06:05 AM

My guess is that the car is pulling slightly to the right on a flat road when you take your hands off the wheel. Over time, it will show up in abnormal tire wear

Jdub 03-28-2013 08:58 AM

Do not sweat the brakes, everyone is getting used to one another (stiction in caliper pucks within the bore, etc.) and there is probably still some amount of air frothing about that will disappear over time. A hard pedal feel will emerge, just give it time.

Cannot comment on the tire spec results as others know plenty more than I do. I had my shop align for street driving (very little camber) as that is primarily how I drive the car, currently. But lots of folks have lots of thoughts about ideal alignment and of course that has everything to do with 'bar size and T-bars, etc.

It would have been nice if they had pulled and readjusted the steering wheel though. I suppose I would wait on that until you are assured your specs as shown above are what you want. Bring them a six pack and tell them first off how nicely the car feels now.

Tremelune 03-28-2013 01:53 PM

The brakes are definitely spongy, but they do have great force when you really get on them. They don't feel terrible, they just feel...kinda icky.

I had the alignment done because the tires that were on there were a decade old and the rear-left was worn to the cords on the inside only. The car handled well before even before the alignment (with a slight tremor at speed that I believe was the tires).

This is what I gave the shop for the wheels/brakes:

Quote:

Work to perform:

1) Four new tires and an alignment.
2) New front brake calipers and hoses.
3) Flush of brake and clutch systems.


TIRES - I purchased a set of Dunlop Direzza ZIIs in 205/55R16 and 225/50R16 that are on their way to your shop from TireRack. They should have my name on them when they show up on Thursday. The tires that are currently on the car are old, and the rear-left is extremely worn on the inside. This is why I suspect an alignment would be wise, though it handles well. Not knowing much about alignment one way or the other, it seems wise to go with stock specs.

Please remove the valve stem protectors and make sure the wheel weights go on the inside. Please replace the wheel lock nuts with the OEM ones provided. Please torque the bolts to spec. Do you perform corner balances? It's a street car only, and I don't think I want to spend the money, but I figured I'd ask.


BRAKES - The front left brake caliper is frozen. It's a bit sticky at stop signs and occasionally it will howl slightly at speed until you tap the brakes. The brakes didn't fix themselves after a good workout.

I have a pair of restored front calipers from PMB Performance that should include everything but the bits that hold them onto the car. The rubber lines are a bit old, so it seems like a good time to replace them (an OEM set will be in the car). The current pads and rotors seem to be in fine shape. Please put the old calipers in a bag and leave them in the car.


FLUSH - The fluid looks good to me, but I have nothing to say that it has been changed in years, so. Please flush the whole brake and clutch systems. ATE Gold or Super Blue, whatever you like. Please make a note of the condition of the fluid that comes out.
They wound up using normal ATE fluid, but that's fine. I just didn't want synthetic or junk. It's not like I'm boiling fluid out here.

rusnak 03-28-2013 02:45 PM

Tremelune,

As I said, brakes should not be spongy.

Normally I would not bother to post a second time, but you should be aware of the safety aspect involved in your braking system. You ought to follow up on this until you can be assured that the repairs are up to par.


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