I have an update on the SEO 1T1 (silicone hose) clamps. As many of you know, the standard rubber hoses used on civilian Caprices and Impalas come with spring type hose clamps. GM did not use the standard spring clamps with the silicone hoses since the slippery silicone hose requires a much higher clamping force than those clamps provide. If you use the standard spring clamps with silicone hose, you risk having leaks occur as well as the silicone hoses popping off at high engine speeds or high coolant pressures.

To provide the necessary clamping force with the silicone hoses, GM used worm gear hose clamps, but not the garden variety you would find at the local hardware store. GM used special lined or extended band clamps which are constructed with an extended band which wraps around the inside diameter of the clamp, covering the worm gear slots and preventing the slots from coming into contact with the hose. These lined or extended band clamps were used to prevent the soft silicone hose from extruding through the slots and becoming cut or damaged under the higher clamping forces required. Therefore if one is upgrading a civilian Caprice or Impala with the SEO 1T1 silicone hoses, one should also use the proper lined worm gear clamps.

The '94-'96 Caprice/Impala uses three different size hoses, requiring three different sized clamps:

* 7 are actually used, but one is supplied with the 1T1 heater hose.
** 4 are required for '94 and early '95 with two reservoir hoses.

From this table you can see that for example the radiator hoses have a 1-7/8 external diameter and should use a size #24 clamp, which is designed for use on hoses from 1-1/8" to 2" in external diameter.

I found GM used p/n 2019422 on the 1T1 silicone radiator hose which is marked as a #24 EXT (also called 24 L) extended band or lined clamp. Unfortunately the factory 2019422 clamp is NOT a 100% stainless steel clamp. It has a stainless band, but the screw is not stainless, and instead is cadmium plated (light gold in color). The ones I got under that number were made by Gold Seal, and labeled 24 EXT. indicating a size 24 clamp with an extended band. I had these clamps on my '88 9C1 and found that the cad plated screw corroded badly over time.

I found a much better version of this clamp under GM p/n 10056745, which is a true 100% stainless (both the band and the screw) #24 size clamp with an
extended band. The ones I got from GM were made by Wittek (who has since gone out of business), and labeled 24 L (lined). A total of 4 of these clamps are
required for the upper and lower radiator hoses. I also found a similar 100% stainless #6 size factory clamp for the reservoir hoses under GM p/n 10266898. Only 2 are required for most '95 and '96 B-cars, however the '94 and early '95 cars have an extra reservoir hose and therefore require a total of 4 clamps.

In summary, here are the best factory clamps:

** 4 are required for '94 and early '95 with two reservoir hoses.

I have not yet found factory lined 100% stainless clamps for the heater hoses, but here is what is required:

* 7 are actually used, but one is supplied with the 1T1 heater hose.

Now, if you want something that is even better than factory, and yet similar to factory in appearance, the ABSOLUTE BEST clamps I have found are ABA acid-resistant 100% 316 stainless clamps which are available through Boat/U.S. Marine (800-937-2628). These are a worm gear style clamp made from 100% 316 stainless (even the screw), which is even more resistant to corrosion than the 304 stainless used in the factory clamps. Unlike standard worm gear clamps, they have a completely smooth inside surface and even feature rolled edges which is even better for the hose than the lined clamps. The smooth inside surface is all around since these clamps do not have slots, but instead the worm gear drives against raised ridges on the outside of the band. Here are the ones to order:

* 7 required for a full matching set.
** 4 are required for '94 and early '95 with two reservoir hoses.

These clamps are expensive, ranging from about $2.05 each for the smaller ones to $2.60 each for the radiator clamps. As usual, the best costs the most. Scott.

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