Rebuilding Brake System for TOWING

[Dan Fahey]

Rebuilding the whole brake system on the SSuperwagon.
Setting it up for Towing..

Questions::::

Any advantage converting the Rears to Disk?
Any differences in the manufacture of new Master Cylinders?
Any Advantage going with Wildwood Front Disks?
What is the Best Brand of Brake Fluid?

SS Wheels are they strong enough?
Using Nitto 255/17/50's Tires

Already purchased from opinion by NavyLifer.
Better Front Disks and Pads.
Purchased a set of Braided Lines.
Already have AirBags
Already have new ABS system

Going to replace 2.56 with 3.08's
OR
Install a 383 and keep 2.56's


Replacing KYB's with Gas Shocks..Probably Belstein.
If you know a better brand or set up please advise..

Dan

[The Lazy Destroyer]

I will be curious on this too, I'm in the same boat with a tow-pack wagon

[Marky Dissod]

Originally Posted by Dan Fahey

Rebuilding the whole brake system on the SSuperwagon.
Setting it up for Towing.

Questions:

Any advantage converting the Rears to Disk?
Any differences in the manufacture of new Master Cylinders?
Any advantage going with Wildwood Front Disks?
What is the Best Brand of Brake Fluid?

SS Wheels are they strong enough?
Using Nitto 255/50R17 Tires

Already purchased from opinion by NavyLifer.
Better Front Disks and Pads.
Purchased a set of Braided Lines.
Already have AirBags
Already have new ABS system

Going to replace 2.56 with 3.08's
OR
Install a 383 and keep 2.56's

Replacing KYB's with Gas Shocks. Probably Bilstein.
If you know a better brand or set up please advise.

Dan

I'd not settle for under 3.23 gear - regardless of engine size - unless I had no plans to EVER tow over 3,000lbs.

Caprice & Roadmaster sedans and wagons with RPO V92 came with 2.93 and were rated to tow 5,000 lbs, with the caveat that the shifter might need to be placed in 'D' to prevent needless 3-4-3-4 huntshifting. (That was in 1994.)

94-96 Caddy Fleetwoods (LT1) with RPO V4P came with 3.42 and were rated to tow 7,000 lbs. LT1 V4P D-cars came with a shift table that prevented needless 3-4-3-4 huntshifting without needing the driver to put the shifter in 'D'
93 Caddy Fleetwoods (L05) with RPO V4P came with 3.73 and were rated to tow 7,000 lbs.

My wagon was recently released from the curse of 2.56 (praise 3.42!). I'm a damned fool for not doing so several years ago.

Though I've never towed a thing, on 4 occasions, I've PUSHED other Caprices [for 10 miles or less] with my 2.56'd wagon. Based on the additional engine heat, maybe I shouldn't have.

On 4 other occasions, I managed to carry 10 other passengers - 11 including me - for about 25 miles each time.

2.56 sucked unwiped @$$ even when I was alone in the car.
With an extra 1,840 lbs of payload in the car, it was torture to accelerate socially, and a mental chore to brake safely - engine and brakes were noticeably hotter than normal for the duration.

Don't know how 2,000 lbs of payload equates to _,____ lbs of towing [before or after factoring in aero drag], but I wouldn't want to tow over 2,000 lbs with 2.56. It'd be a waste of fuel and transmission longevity.

If I could afford the expense, and I had a car with 2.93 or less, I'd look for 3.23 or 3.42 or 3.73 to tow over 3,000 lbs. Wouldn't want to settle for 3.08, even if that's what I already had.

Don't know if rear disks are better than 11" by 2" drums.
Don't know about master cylinders.
A front disk rotor upgrade is ALWAYS recommended.
There are better brake fluid brands than ATE, but ATE's pretty good for the money.
Don't know if SS wheels are strong enough, but I'd definitely go with taller tires, regardless of wheel size.

[Navy Lifer]

Originally Posted by Dan Fahey

Rebuilding the whole brake system on the SSuperwagon.
Setting it up for Towing..

Questions::::

Any advantage converting the Rears to Disk?
Any differences in the manufacture of new Master Cylinders?
Any Advantage going with Wildwood Front Disks?
What is the Best Brand of Brake Fluid?

SS Wheels are they strong enough?
Using Nitto 255/17/50's Tires

Going to replace 2.56 with 3.08's
OR
Install a 383 and keep 2.56's


Replacing KYB's with Gas Shocks..Probably Belstein.
If you know a better brand or set up please advise..

Dan

Dan,

Here's my take:

1. rear disc: for your purposes, IF you are staying with a larger (17") wheel, the WRDC kit, with a 13" Corvette Z51 rear rotor, is worth consideration--it will clear the Impala SS wheel. Using a standard Impala SS rear disc package would not be of any benefit over the existing drum setup, but going to the Corvette-based system (better rotor options) is going to provide better brake durability. The only drawback to this, for towing, is that the park brake (aka "emergency brake") is quite small, and is not really designed to STOP a car (not to mention your towing load--GVW over 10K lbs) in the event of a hydraulic system failure.

So, unless you think you must have discs for the rear, I recommend staying with drums, and just maintain the crap out of them. I am not certain about this, but I do not think the Fleetwood "commercial chassis" rear drums (11.15 x 2.75) can be bolted-on to a wagon rear axle, since the bearing sizes, backing plate flange pattern, and axle standoff measurements are probably not the same as the stock wagon's 11 x 2 brakes. IF the larger drum package DOES fit, it would be a plus worth considering.

2. master cylinders: OE replacements from ACDelco are perfectly satisfactory, and make for easy changeout. There are several sizing options available--not sure what wagon uses, but 1.125 (1-1/8") is common, used on Impala SS & most Caprice applications, and 1.25 (1-1/4") is available, from 9C1. The larger MC, with no other changes, makes for a "heavier" pedal (more pedal force for the same braking level), if you stay with the stock wagon brake pedal. You can change over to the Impala SS & 9C1 (94-96) pedal assembly and brake booster, which are designed to work together, to improve the pedal ratio and bring the pedal force required to achieve equivalent braking back to more "normal" levels.

Also, all 94-96 cars with ABS, regardless of model, used the same proportioning valve. Unless you go to a rear disc setup, I do not recommend installing the "stealth" mods to the combination valve without doing other things. I would consider it OK to plumb in a manual-adjust proportioning valve on the rear brakes (drums) in combination with the stealth mod.

3. Wilwood "discs"--are you referring to OE replacement calipers, or a "Big Brake" package, as offered by TCE? If you mean just replacement calipers, the D52 unit is the one viable choice, however, even with it's twin piston design, it offers less total piston area than the OE unit. Other than the weight difference, the Wilwood D52 is more about cosmetics than any advantage(s) over stock calipers, which are totally reliable when properly maintained.

Bottom line, the shortcomings of the stock system begin with the rotors, and putting a cool new caliper into the mix doesn't change that reality. Better to consider the HD12 rotors or a big-brake package, which will include a caliper change anyway.

4. Brake fluid - ditto MD's comments
5. Wheel strength - steel cop wheels are better, for 17's, good luck finding anything equivalent. Ditto on larger tires
6. Do not try to tow with 2.56 ratio--look at what GM used, 2.93 for LT1 cars and 3.23 for L05 cars, as minimums. Consider 3.42 ratio.
7. Bilstein is always a good choice--but also think about sway bars, by up-sizing the front (from 28mm to 30mm minimum) and adding a rear bar, which may also require a rear LCA change.

[Dan Fahey]

Good Information...

Back in 1995, towed my 1969 Impala from Atlanta with my 1969 Impala SS using a heavy U-Haul Trailer and NO Airbags..
Could not drive faster than 50mph without a good scare.

The 95SS had 3.08's and pulled well. Braked Well despite the weight.
AND
Got 18mpg...Holding at 50mph probably was smart anyway.

So I still have the 95SS 3.08's and original posi to use..
Which is a step better than the 2.93's...

Figure 1500# Trailer, 4500# Car and gear yields about 6000# Towing.
Wagon weighs 4800#, has airbags, Ebach Front Spring and Bar.

FWIW the damn car turns insides a Toyota..

Good Information that the Wildwoods are not a Performance Advantage.
If the car has ABS and add the Steath Bolt Mod.
The extra weight of tools and trailer weigh would help rear braking.
Without the ABS should regulate the Drums..

What REAR Stabalizer Bar is a Bolt-on for wagons?

Dan

[The Lazy Destroyer]

Dan,

What were you planning on towing (weight)? EDIT: Nevermind, you must have posted while I was posting. I see your 6k lbs

In my case I will be towing the Caprice (~3700 lbs) + trailer weight. But obviously I plan on having trailer brakes and a good brake controller.
I will probably try and copy Palamino's setup since he's doing something similar to what I want and he is happy with his results it appears.

[BALLSS]

Dan

given the intended tow weight of 6k lbs I would:

1. gear 3:42
2. install external tranny cooler
3, have brakes on the trailer

higher gear ratio will add more load to the tranny, IMHO, under towing conditions.

agree on SS brake lines

[Dan Fahey]

Originally Posted by BALLSS

Dan

given the intended tow weight of 6k lbs I would:

1. gear 3:42
2. install external tranny cooler
3, have brakes on the trailer

higher gear ratio will add more load to the tranny, IMHO, under towing conditions.

agree on SS brake lines

Hmm going to new 3.42's is going to kill daily gas mileage.
Biggger Tranny cooler is a given.
Though the car already has the Stock one.

The SS is an easy mod that should be done anyway.
Going to Baer or Wildwoods would not be an advantage.
Brakes on the Trailer is Mandatory.

Looking more reasonable to get an SUV set up for this.
The GM 5.3 Liter seems to be a popular choice by other racers.

Dan

[Marky Dissod]

Originally Posted by Dan Fahey

Hmm going to new 3.42's is going to kill daily gas mileage.

3.42 & up tends to IMPROVE metro/urban MpGs.

Originally Posted by The Bolt-On Terror

I drove my Impala with the stock engine and 5.57 gears for several weeks to work 2 summers ago and got 19 MpG.
No high speed interstate miles, 44 miles one way with 46 intersections/potential stops.
I'm sure mileage would have been worse at interstate speeds.

Speaking from indirect experience on this, as I recently liberated my wagon from 2.56 with 3.42 …
After revising the conservative driving portion of the 'Normal Up/Down Shift Points' table (under 19% TPS), it doesn't matter whether I drive cowardly, hypermilingly, conservatively, chaufferly, or socially normally.
13MpG Metro/urban, if I use 19% TPS or less - which 3.42 makes orders of magnitude easier than 2.56.

To score under 13MpG City NOW, is actually much more difficult than it was with 2.56, and SO MUCH MORE FUN!
(Last few times I got under 13MpG at the pump with 3.42, I reminisced while the gasoline flowed, baby …)

My highway MpGs haven't changed. 3.42 makes it too easy to 'thread' highway traffic in 4th & 3rd.

FYI
3.73 & 29.50" tall tires = 3.42 & 27.05" tall tires - identical engine RpMs in all gears, at all road speeds
3.73 & 27.92" tall tires = 3.42 & 25.60" tall tires

3.42 & 29.50" tall tires = 3.23 & 27.86" tall tires
3.42 & 27.11" tall tires = 3.23 & 25.60" tall tires

3.23 & 29.50" tall tires = 3.08 & 28.13" tall tires
3.23 & 26.85" tall tires = 3.08 & 25.60" tall tires

3.08 & 29.50" tall tires = 2.93 & 28.06" tall tires
3.08 & 26.91" tall tires = 2.93 & 25.60" tall tires

and in case you were wondering

3.42 & 29.50" tall tires = 3.08 & 26.57" tall tires
3.42 & 28.43" tall tires = 3.08 & 25.60" tall tires

If I had larger wheels, I'd try to get closer to 29.50", but with 15" wheels, 28.87" is as tall as I can go.

Originally Posted by Dan Fahey

Bigger Tranny cooler is a given.

+1.
You may wish to give it its own dedicated fan?

[BALLSS]

Originally Posted by Dan Fahey

Hmm going to new 3.42's is going to kill daily gas mileage.


Looking more reasonable to get an SUV set up for this.
The GM 5.3 Liter seems to be a popular choice by other racers.

Dan

"towing 6k lbs" is going to kill your milage. The 3:42's will just allow the gear advantage of the wagon to pull the load and reduce the strain on the transmission.

the SUV thing "in general" is more suited for towing 6k trailer. Assumeing it is set up with a "tow package" which typically consists of larger cooling system, external trany & oil coolers, beefier suspension and in some cases braking systems and a hitch/trailer light/brake wiring.