DOT Fluid Question for Towing

Dan Fahey · 02-17-2017, 06:18 PM

Finishing up rebuilding the front end on the 1994 Caprice Wagon.
This is the Tow vehicle for the 95 Impala SS.

Not exactly S/SS material but is about Brakes.
The front end rebuild gets new everything.
Steering box, centerlink, tie rods, and control arms...
and a new Flaming River Steering Arm....the upgraded works.

The Brake system gets a make over.
New Master Cylinder even though the original is fine.
Calipers and Rotors are fairly new and ran Hawk Front Pads.
All that is now new or recondition back to new painted and assembled.
Again with a fresh set of Hawks Low Dust Pads.

The Rear gets new Spring kit, Wheel Cylinders, Riveted Brake Shoes and using a HD 11 Inch Drum.
The originals had 11.060 stamped on them, the new 11.090 and feel heavier.

The old brake system used GM DOT 3 but looking at DOT 3 Synthetic.
But there is also DOT 3/4 and DOT 4.

Synthetic has a higher boiling temp over standard DOT.
Looking at going with Synthetic DOT 3.

Is there any advantage using DOT 3-4 or DOT 4 over DOT 3?

Dan

Roberte · 02-17-2017, 06:58 PM

Back in the day, syn was not compatible with current
rubber compounds. Might want to check.
Bob

SSDiv6 · 02-17-2017, 07:05 PM

For your application, I would recommend Amsoil 500 DOT 3 High-Performance Synthetic Brake Fluid.

In the early days of synthetic fluids, there were problems with seal compatibility. The new brake fluids do not have the issue.

MAURICE BLENDHEIM · 02-17-2017, 08:49 PM

Why wouldn't you just use the tried and true Dot 3? Still used in many Industrial Applications where load and heat are one of the main factors in operation. Besides its cost effective and when the unexpected happens, almost everyone has some. MB.

Dan Fahey · 02-18-2017, 03:28 AM

Quote:

Originally Posted by MAURICE BLENDHEIM

Why wouldn't you just use the tried and true Dot 3? Still used in many Industrial Applications where load and heat are one of the main factors in operation. Besides its cost effective and when the unexpected happens, almost everyone has some. MB.

Because the Synthetics have a higher boiling temp rate.

I am also flushing the whole system..

D

02-17-2017, 06:18 PM	#1
Dan Fahey VIP Member Join Date: Oct 2008 Posts: 2,126 Likes: 1,084 Liked 184 Times in 113 Posts	DOT Fluid Question for Towing Finishing up rebuilding the front end on the 1994 Caprice Wagon. This is the Tow vehicle for the 95 Impala SS. Not exactly S/SS material but is about Brakes. The front end rebuild gets new everything. Steering box, centerlink, tie rods, and control arms... and a new Flaming River Steering Arm....the upgraded works. The Brake system gets a make over. New Master Cylinder even though the original is fine. Calipers and Rotors are fairly new and ran Hawk Front Pads. All that is now new or recondition back to new painted and assembled. Again with a fresh set of Hawks Low Dust Pads. The Rear gets new Spring kit, Wheel Cylinders, Riveted Brake Shoes and using a HD 11 Inch Drum. The originals had 11.060 stamped on them, the new 11.090 and feel heavier. The old brake system used GM DOT 3 but looking at DOT 3 Synthetic. But there is also DOT 3/4 and DOT 4. Synthetic has a higher boiling temp over standard DOT. Looking at going with Synthetic DOT 3. Is there any advantage using DOT 3-4 or DOT 4 over DOT 3? Dan

02-17-2017, 06:58 PM	#2
Roberte Junior Member Join Date: Dec 2014 Posts: 68 Likes: 166 Liked 14 Times in 8 Posts	Re: DOT Fluid Question for Towing Back in the day, syn was not compatible with current rubber compounds. Might want to check. Bob

02-17-2017, 07:05 PM	#3
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 3,023 Likes: 706 Liked 1,514 Times in 563 Posts	Re: DOT Fluid Question for Towing For your application, I would recommend Amsoil 500 DOT 3 High-Performance Synthetic Brake Fluid. In the early days of synthetic fluids, there were problems with seal compatibility. The new brake fluids do not have the issue.

02-17-2017, 08:49 PM	#4
MAURICE BLENDHEIM Senior Member Join Date: Jun 2011 Location: Langley (no igloos), British Columbia, Canada Posts: 565 Likes: 305 Liked 264 Times in 85 Posts	Re: DOT Fluid Question for Towing Why wouldn't you just use the tried and true Dot 3? Still used in many Industrial Applications where load and heat are one of the main factors in operation. Besides its cost effective and when the unexpected happens, almost everyone has some. MB. Last edited by MAURICE BLENDHEIM; 02-17-2017 at 08:51 PM.