So-so brakes on my 73

Deschodt · 05-09-2005, 12:50 PM

Here's the deal, I got a 73.5T that had a tendency to go from side to side under braking. Not just pulling to one side, mind you, but rather go a bit left, then a bit right, then straight - under hard braking only... I should mention the car has S options, including brakes and torsion bars.

Kinda puzzled me and the wrench alike. He started by suggesting my 205x15 were too big for the rim so we downsized to a stock tire... He also played a bit with the suspension and corner balanced it - more or less - and it's noticeably better now but when braking hard you can still feel a bit of side to side pull.
Nothing to cause a problem but it's there, like pressure equalizes itself eventually.

At that point he mentioned that the S brakes of that era are somewhat crappy (no offense, I hope) 3 piece calipers and I might want to update to more modern ones... Is that a fact ? I am thinking I might start with new hoses all around just in case they're swollen internally...

TIA ! Greg.

Bill Verburg · Bill Verburg's Garage

Get the suspension and steering up to snuff first

Early_S_Man · 05-09-2005, 02:35 PM

Greg,

Your stability problem sounds like a toe-out problem to me ... though a tire problem such as out-of-round could be the problem, too!

You need a change of wrench, too ... 205s aren't too wide for 6" wheels, in fact, 215s will work fine!

As far as the brakes go ... he's a bit off in left field with respect to reality! Rebuild the calipers, and your car will stop better than an SC or Carrera, since it is lighter! The non-boosted brakes may require a bit more pedal effort, but they are much easier modulated than the later cars, too!

Forget the upgrades ... just get everything back to factory-new working conditions, and you will be surprised how well it performs, provided that you have descent tiresin place!

304065 · 05-09-2005, 02:53 PM

Ok, I use 225's on 6's and there's nothing wrong with the braking.

And I use S calipers, nothing keeping me from braking at 1g with those.

May I echo the advice from the Gentleman from San Angelo, that a caliper rebuild and check of the hoses might fix your problems? When was the car corner balanced/aligned last?

LakeCleElum · 05-09-2005, 02:57 PM

Greg: I have a '73.5T and had the same exact problem. As John said, replace your flexible hoses. Mine were orginial and the right front was plugged completely. You'll be amazed at the difference...

pwd72s · 05-09-2005, 03:01 PM

I recently had a lot of work done to my car, so it's difficult to assess which area did the most improvment...but it was expertly corner balanced and aligned. The transformation was very remarkable, since not much had been done in the past few decades.

rjay · 05-09-2005, 03:23 PM

I think Bill could be on the money. Check the suspension. The fact that the car is hunting suggests to me that there could be some suspension binding or some worn suspension parts, bearings, monoballs etc. As to the S calipers, the knock on them is that they tend to flex a bit under hard braking. If I were tracking the car, I'd consider upgrading, if not, I'd just rebuild them.

Deschodt · 05-09-2005, 05:24 PM

I will do the hoses first, but I suspect you are on to something with suspension.... Tonight after I finished installing the RS door panels I had a handy ruler in hand and measured the fenders height...

Driver side is 25.5 F 25 Rear
Pass side is 26 F 26.5 R

Ok, he supposedly corner balanced (approximately) and I know correct diagonals may sometimes result in varying heights, but that seems very much off to me... Plus the car looks like it's on stilts... Hoses first, then I'll take it to Dave white Motosports, he knows a thing or 2 about suspensions, I suspect !

Besides it was idling perfectly before staying at the mechanic's and now he said it blew the pop off valve when he started it (mounted incorrectly by PO?) and he put it back on - now it hunts for idle... I gotta go reseal that too I bet !
Yikes - should have stayed home for my money !