TorchTarga94

I was hoping you guys could help me out finding the correct size spring clamps for the radiator hoses? I am referring to the OEM style Constant Tension Spring clamps:





Right now I am using standard SS worm gear clamps from the auto parts store and don't really care for the way they look or function. Would prefer the OEM style. My heater hoses still utilize the OEM spring clamps and I can see they are SAE size "27" where the hoses attach to the water pump. How about the actual lower and upper radiator hoses, can any of you look on the clamp and see what size they are? Can't seem to find any mention of it in the FSM. The size of the clamp is located on one of the clamping ears.

Any help is greatly appreciated.

P.S.- I am replacing all of my hoses and want to use the OEM clamps if possible. Look neater, more uniform seal.

WVZR-1

Is this for a '94 that still has the "tee" in the mix or have later been used? I have the answers I believe but you plan on doing what?

TorchTarga94

It is a 94' but the "T" in the upper radiator hose has been bypassed in lieu of the 96' hose. The Throttle Body lines have also been bypassed. If you can suggest a brand and size of clamp, whether it be the OEM constant tension, or another type that is a little higher quality than a standard parts store worm gear that would be great. Like I said, looks like the heater hoses where they attach to the water pump use a SAE-27 clamp. Just need the size of the upper and lower rad hoses (4 clamps).

I am replacing the heater hoses and coolant radiator hoses and want to use one style clamp exclusively (preferably OEM constant tension)

I appreciate the help!

WVZR-1

Not having the aftermarket hose diameters (it's likely important) I'm going to post a link to CTB HOSE CLAMP CHART and you can calculate your sizing. I'll mention the most frequently used GM METRIC SIZES and more but for the time being this is maybe industry standard. I would likely choose maybe ISUZU just because of the known quality but there are multiple sources. MCMASTER if you change the Metric spec to SAE?

GM clamps are CTB with the 15mm spec and there's maybe a few CTN (12mm but not for coolant hose larger diameters).

https://www.rotorclip.com/cat_pdfs/ctb.pdf

TorchTarga94

I am using this hose for the lower:

ACDELCO 24409L {#88908698} Molded Coolant Hose; 1-9/32" x 1-21/32" x 24 19/32"

And this hose for the upper:

ACDELCO 24408L {#88908697} Molded Coolant Hose; 1-9/32" x 1-3/8" x 19-5/16"


I appreciate the chart. Still not clear on which clamp I need. If you are using the OEM style constant tension can you see what the number is on the clamp? They all work for a specific range of hose. I.E. - Size 32 (Fits Hose I.D. 1-1/2" to 2", Clamping Range 1-9/16" to 2-1/2")

I just want to make sure I select the correct range clamp for our size radiator hoses.

WVZR-1

You're using an after-market hose, the dimensions on those ACD hoses I believe are ID. Do you have the hoses yet? Those hoses wouldn't be my first choice either.

A '96 spec hose I'd think at the radiator a 47 upper, at the water pump 42. For the lower at the water pump another 42 and at the radiator lower another 47. You would need to check those against the hoses that you buy but ...............

TorchTarga94

Yes, the outside the diameter is 1-3/4"

WVZR-1

If you measure 1 3/4" then I'd think you want 50. Convert columns D1 & D2 to SAE however you might like and compare. I have 40, 42, 50 & 53 here with me now.

TorchTarga94

Thank you!

WVZR-1

I mentioned using Isuzu and I believe the Isuzu product is likely 20mm wide, it would likely have been used on some of the later GM MD/HD Isuzu powered stuff. I had easy access to Isuzu and when doing clamps (CTB style) I nearly always used their product.

Is there an Isuzu MD dealer in the area? Take your hoses if you've got them to try. A GM 20mm with a 1 3/4 OD might be 11519578 and maybe all of the later GM production used the 20mm wide product. I used the C4 information I'm familiar with for the information previously. I may toy with some 20mm wide product and post back.

TorchTarga94

WVZR-1 - Just wanted to update this thread. I appreciate all your help and advice last Sunday. Instead of going with the OEM style constant tension clamps I went to my local Napa and picked up these Ideal Brand constant tension hose clamps. They are completely smooth on the inside and use belleville washers to provide a spring or tension. The band is also a little wider than traditonal worm gear clamps or the oem style tension clamps. These are great and very heavy duty. They were highly recommended on a Porsche forum. Cost about $4.50 a clamp.

WVZR-1

I've a friend that I believe uses that style clamp on some of the vehicles he services. There's a newer Ideal that's maybe better functioning with two bevels providing the clamping surface that he uses also. Both work.