1970 Corvette hose clamps

[D S.]

What correct clamps and color of clamps goes on a 1970 Corvette LS-5 with AC and power steering and power brakes?

1.) PCV hose on both ends? Pinch clamps?
2.) Brake booster hose on both ends?
3.) Power steering hoses?
4.) Fuel pump hoses?
5.) Brass overflow tank hose?
6.) Brass overflow tank to radiator hose?
7.) Both ends of the air cleaner to passenger side valve cover? 1-1/2" dated tower clamps?

I think I'm clear on the type of clamps on the two heater hoses to the water pump and intake and the hose to the underside of the overflow tank. Dated tower clamps of sizes 1-1/16" and 1-3/16".

The JG seems to have them depicted or mentioned on several different pages or no mention of hose clamps at all but after I've read archive discussion after discussion there seems to be running differences in hose clamp applications in some areas.

Thanks,
Scott Sims
Texas Chapter

[Paul O.]

Re: 1970 Corvette hose clamps

Scott the power steering hose only 1 hose had a clamp it was the return line I don't remember the name of this style clamp its finish was some what like the tower clamps and was round ring about 1/4" wide and crimp style tool was used to compress the band forcing a section of the band to raise up reducing it size to secure the hose. The other hoses its been a while would have to look at some photos I have. Paul 18046

[D S.]

Re: 1970 Corvette hose clamps

A couple of clamp types routinely mentioned here on the TDB aren't in the JG that I could find. I have the 1970-1972 4th edition. Those are the green spring clamps with the square tangs (on what hoses?) and the type of clamps that hold the PCV hose onto the PCV and at the carburetor. The JG doesn't mention clamps on the PCV hoses but I have seen them on cars with pinch clamps or no clamps at all.

[Terry M.]

Re: 1970 Corvette hose clamps

PCV hoses, I think, get green spring clamps. Check the AIM for the location. I believe there are only two spring clamps, one at each end of the hose assembly. Three spring clamps are too many.

Power brake booster (each end) gets black spring clamps.

Your fuel pump may have green spring clamps on the supply side, and either small stainless steel tower clamps or, I think, yellow spring clamps on the return side. For the return line look at the gas tank and see what is there. If those are original they will give you a clue as to what could be at the front. If they are not original you have two choices: 1) guess 2) find someone with a car built close to yours and copy what they have.

Remember ALL spring clamps from 1968-1972 had the square ears. They will cut your hands. In the 1968-1972 range Chevrolet NEVER used worm clamps on the fuel, PCV, or vacuum lines.

Air cleaner crankcase vent inlet hose should have the dated 1.5-inch tower clamps. See the date note in the TIM&JG. I have seen one very original Corvette with no clamps on the crankcase vent inlet hose, but I believe that is not typical factory production.

The TIM&JG is no help for AC equipped cars regarding heater hose clamps. We have to work on that part of the manual. Let us know what your research reveals so we can add it to the database. Or maybe someone with a real original LS5 C60 car will post here. I doubt there will be any difference in the heater hose clamps from 1970-1972, but more data points are better.

[D S.]

Re: 1970 Corvette hose clamps

PCV hoses, I think, get green spring clamps. Check the AIM for the location. I believe there are only two spring clamps, one at each end of the hose assembly. Three spring clamps are too many.

Power brake booster (each end) gets black spring clamps.

Your fuel pump may have green spring clamps on the supply side, and either small stainless steel tower clamps or, I think, yellow spring clamps on the return side. For the return line look at the gas tank and see what is there. If those are original they will give you a clue as to what could be at the front. If they are not original you have two choices: 1) guess 2) find someone with a car built close to yours and copy what they have.

Remember ALL spring clamps from 1968-1972 had the square ears. They will cut your hands. In the 1968-1972 range Chevrolet NEVER used worm clamps on the fuel, PCV, or vacuum lines.

Air cleaner crankcase vent inlet hose should have the dated 1.5-inch tower clamps. See the date note in the TIM&JG. I have seen one very original Corvette with no clamps on the crankcase vent inlet hose, but I believe that is not typical factory production.

The TIM&JG is no help for AC equipped cars regarding heater hose clamps. We have to work on that part of the manual. Let us know what your research reveals so we can add it to the database. Or maybe someone with a real original LS5 C60 car will post here. I doubt there will be any difference in the heater hose clamps from 1970-1972, but more data points are better.

Thanks, Terry. My post on hose clamps got started because a couple of days ago I noticed my PCV hose was flattening and then I discovered I have the wrong hose and wrong PCV in my valve cover. Also because of the hose bend it was restricting air flow, too. I have a dual snorkel air cleaner and the hose goes underneath the left snorkel. Then I got to wondering why there wasn't a PCV hose clamp on either end and began taking note of other hose clamp issues on my car. I went through several archive posts on the TDB and JG and noted there were several clamp types mentioned for various applications: SAE type D, Sure-Tite worm gear (SAE type F), dated tower clamps of various sizes (SAE type C radial), green and phosphate black spring clamps with the squared tangs, the smaller Type Ds with either the number 2 or 23 (???) stamped on them. There doesn't seem to be enough information in the JG about them and that may be because there isn't enough information about their usages. Perhaps a listing of the type clamps and applications with illustrations on one page of the next edition of the 1970-1972 JG might help.

Scott

[Terry M.]

Re: 1970 Corvette hose clamps

Scott,
There is not enough information about hose clamps in the 1968-1972 TIM&JG, and as you have noted -- what information is there is scattered in different parts of the manual.

The reason for that is because the manual was, and is, first and foremost a judging guide. The items in it are organized to fit the judging sheets, and the mechanical team judges some clamps and the chassis team judges some. So the clamps that each team deals with are described with the item that is being judged, in the section that belongs to the team judging it.

When we wrote the manual we had to decide which goal it was to meet -- judging or restoration. Judging won.

You want a page with all the clamps on it? Make your suggestion to the team leader(s), and the Judging Manual Review Team will consider it. It is time to rewrite at least one of them, and we want and need more pages so we can charge more for it.

[D S.]

Re: 1970 Corvette hose clamps

Scott,
You want a page with all the clamps on it? Make your suggestion to the team leader(s), and the Judging Manual Review Team will consider it. It is time to rewrite at least one of them, and we want and need more pages so we can charge more for it.

Love your sense of humor about charging more. All kidding aside the JG is a testament to the research, input, and efforts put into it to be as thorough as possible given the information available. I've about worn out the pages on my 4th edition and some of the pages are coming off the spring holder. I may take the clamp information from the JG and off the TDB and make notes on the back cover of the JG. Thanks, Terry.

[D S.]

Re: 1970 Corvette hose clamps

Did I read somewhere in the JG that dated tower clamps can be used with dates (Q/YY) up to three years prior to the build date of the Corvette?

[Steven G.]

Re: 1970 Corvette hose clamps

Great information Scott and Terry !! I have learned that geared clamps were not used and the clamps that were used will cause a person to bleed, so that's why they were replaced with geared clamps over the years. Steve

[Terry M.]

Re: 1970 Corvette hose clamps

Did I read somewhere in the JG that dated tower clamps can be used with dates (Q/YY) up to three years prior to the build date of the Corvette?

Yes, you read that right. Strange as it seems. They must have bought a truckload of those clamps and doled them out like they were gold.

[Terry M.]

Re: 1970 Corvette hose clamps

Great information Scott and Terry !! I have learned that geared clamps were not used and the clamps that were used will cause a person to bleed, so that's why they were replaced with geared clamps over the years. Steve

[D S.]

Re: 1970 Corvette hose clamps

Looking at what some of those pinch clamps and tower clamps are getting on eBay you'd think they were as rare as frog hair.

The only exception to the dating on the tower clamps was in the smog pump section where the AIR hose clamps should be dated within a year of the build date of the car. As a matter of preference I would rather have the tower clamp dates on my car very close to the build date. My car was built in the first quarter of 1970 so 4/69 to 1/70 would be ideal. Since 1970 was a short production year would that mean there were less than three quarters in that production year?

True about those worm gear clamp installations. I've actually seen rubber oozed out the slots of the worm gear bands from being overtightened.

[Terry M.]

Re: 1970 Corvette hose clamps

Since 1970 was a short production year would that mean there were less than three quarters in that production year?

Wittek made those clamps for ALL Chevrolet model lines as well as Ford and anyone else who wanted to buy them. I'm sure they pumped them out by the millions. There were four quarters in 1970, just like every other calendar year.

Now since Corvette production in 1970 MODEL YEAR began the beginning of January 1970 and ended near the end of July 1970 one would not expect to see 4th quarter of 1970 on the clamps. I have 4th quarter 1969 clamps on my end of January 1970 and I would expect a late July Corvette just might have 3rd quarter 1970 on some clamps -- maybe. I think I might have some 3rd quarter 1969 clamps on the car, but I would have to look to verify that for certain. I know there is 1st quarter 1970 on there.

So short story 1970 model year production went just beyond two quarters, and there is the possibility of having four or more different quarters showing on some clamps or other dated parts. I guess it should be obvious that one wouldn't expect to find all four quarters represented on the same car.

We probably should spend more time talking about the screw size on the tower clamps rather than beating the obvious date issue to death. And then there is the font style and placement on the SureTite, but that was covered in a thread that is in the archives. There is a lot more to clamps than meets the eye.

[D S.]

Re: 1970 Corvette hose clamps

<snip>We probably should spend more time talking about the screw size on the tower clamps rather than beating the obvious date issue to death. And then there is the font style and placement on the SureTite, but that was covered in a thread that is in the archives. There is a lot more to clamps than meets the eye.[/quote]


Thanks, Terry. I have several original Sure-Tite 32s and 28s and smaller and also noted the differences in fonts and where the word 'Sure-Tite' is located, all being original Witteks. I also noted the differences in the sizes of screws on the various sizes of tower clamps.

Spring clamps with the square tangs. What is the significance of the <U> stamped on some of them such as the ones for the PCV and brake booster hoses?

Funny how the 1-1/2" AIR tower clamps have a recommended date of being within a year of the build date of the car and the 454 crankcase ventilation 1-1/2" tower clamp three years but the 1-1/16" and 1-3/16" heater hose tower clamps are silent on dates, only that they be dated. I would assume they also fall under the three year rule?

I think I'll revisit the archives again.

[Terry M.]

Re: 1970 Corvette hose clamps

[QUOTE=D Scott Sims (43568);
Spring clamps with the square tangs. What is the significance of the <U> stamped on some of them such as the ones for the PCV and brake booster hoses?

Funny how the 1-1/2" AIR tower clamps have a recommended date of being within a year of the build date of the car and the 454 crankcase ventilation 1-1/2" tower clamp three years but the 1-1/16" and 1-3/16" heater hose tower clamps are silent on dates, only that they be dated. I would assume they also fall under the three year rule?

I think I'll revisit the archives again.[/QUOTE]

Just a guess on my part, but <U> is probably a manufacturer's mark of some kind. I believe the size is keyed to the color of the spring clamp.

I'm going to have to check the tower clamp sizes in the TIM&JG, but methinks you have too many sizes dated. I know one of the heater hose sizes are NOT dated, but have DCM stamped on them. The reason for that is explained in the TIM&JG -- at least it is in the latest version, and I think the version before that also. I can't remember all these sizes, but I thought the Mark IV PCV inlet air hose clamps were a unique size -- look in the air cleaner section. Maybe more research will straighten out your questions before I get home to my TIM&JG.