[staleg]

Due to very limited space around my heater, I need to enlarge the 5/8" heater hoses to 3/4" on one end. There isn't enough space for an adapter fitting.

Is this possible, for instance by using heat?

Or is it possible to have a couple of 5/8" heater hoses custom made with a short area of 3/4" diameter in one end?

[cobalt327]

Trying to stretch a 5/8" heater hose out to 3/4" will weaken it IMHO. You might get it to physically fit, but the strength would be compromised I believe.

No room for a reducer like this (they also come in brass that are shorter)?

[staleg]

Thanks for your quick answer. I don't think it's room for the reducer.

But what about these that I just found on Summit Racings homepage:
Summit Racing® Heater Hose Adapters SUM-390007 - SummitRacing.com

Heater hose adapters. But I don't understand from the photo how they work...
Do you simply put the 5/8" hose into the 3/4" hose and clamp the connection?? Will that be leak free?

If so, I might have enough space for this.

[123pugsy]

Looks like you change the whole 5/8 hose to 3/4" and then use a small pce of hose inside the 3/4 hose to fit at the 5/8 end and of coarse the new 3/4 hose will fit the big end as req'd.

My guess.

[cobalt327]

Originally Posted by staleg

Thanks for your quick answer. I don't think it's room for the reducer.

But what about these that I just found on Summit Racings homepage:
Summit Racing® Heater Hose Adapters SUM-390007 - SummitRacing.com

Heater hose adapters. But I don't understand from the photo how they work...
Do you simply put the 5/8" hose into the 3/4" hose and clamp the connection?? Will that be leak free?

If so, I might have enough space for this.

The Summit connector would use the 3/4" hose that's included over the nipple on the heater, then the included 5/8" OD piece is pushed halfway into the 3/4" hose, then your 5/8" hose is pushed over the other half of the included 5/8" OD piece and the whole thing clamped down.

[staleg]

Thanks for your answers.
Unfortunately, the holes in the firewall aren't large enough for 3/4" hoses.

If I understand Cobalt 327 corrct, I'l try the Summit reducer.

[cobalt327]

Originally Posted by staleg

Thanks for your answers.
Unfortunately, the holes in the firewall aren't large enough for 3/4" hoses.

If I understand Cobalt 327 corrct, I'l try the Summit reducer.

The Summit part still requires you to put the 3/4" supplied piece of hose onto your heater barb. It seems to me if that would fit, so would a length of 3/4" heater hose. I must be missing something...

[MARTINSR]

There are many heater hoses that are 5/8" on one end and 3/4" on the other.



This could be one, don't know the exact sizes.



Anyway, make a pattern of your hose out of some brake line or something stiff and go to your local REAL parts store (not a McParts store like the Zone) and ask to see their hose selection and they will be happy to let you go thru them to find something that will work.

Now, often you will buy a longer hose than you need and cut it to length. My brother sells moulded hoses like the originals for 50's and 60's Buicks made from hoses right off the rack at the local parts store. He spent the time to hunt them down, he now buys hoses for late model applications and cuts them to length to fit right on the old Buicks.

At the NAPA store I worked at we had hundreds of these hoses, heater and radiator and would do this all the time for people. You would be very surprised at how many vintage cars radiator hoses can be made up this way.

Brian

[cobalt327]

Good point, Brian. I once had to make do w/a molded hose that was originally for a 3.0L Voyager, to use for the bypass on my 468 BBC in the Camaro. Worked so good I left it on.

[staleg]

What would be perfect for me is 3-4 ft of straight 5/8" hose, with a 3/4" enlargement in one end.

[cobalt327]

Originally Posted by staleg

What would be perfect for me is 3-4 ft of straight 5/8" hose, with a 3/4" enlargement in one end.

Gates Dual I.D. Heater Hose
Specially designed for heater hose applications requiring changes in diameter.

For part numbers, see page A26, here.

[MARTINSR]

Originally Posted by staleg

What would be perfect for me is 3-4 ft of straight 5/8" hose, with a 3/4" enlargement in one end.

You need to get down to a real parts store and they will likely have just what you need. If they don't have it in stock they will be able to get it for you.

Brian

[dinger]

Originally Posted by cobalt327

Trying to stretch a 5/8" heater hose out to 3/4" will weaken it IMHO. You might get it to physically fit, but the strength would be compromised I believe.

No room for a reducer like this (they also come in brass that are shorter)?

I may be missing something here, but why would you not run a 3/4 inch hose from the heater core, say about 10 inches long, then put this reducer and run 5/8 from there on out?

[staleg]

The holes in my firewall accepts no bigger than 5/8" hoses, and the distance from the heater outlest to the inside of the firewall is very short. That's why.

I'll check out the Gates part numbers. Thanks for the link!

[123pugsy]

Originally Posted by staleg

The holes in my firewall accepts no bigger than 5/8" hoses, and the distance from the heater outlest to the inside of the firewall is very short. That's why.

I'll check out the Gates part numbers. Thanks for the link!

Try warming it up with a heat gun. It should soften up enough to go on. I've done it with a lot of hoses with no issues.