Heater hose diameters???

So, got a leak in my 94 super custom. im not going to find the oem shaped heater hoses in the USA, ive got a leak in one up front where it attaches to the heater controll valve. If anyone knows the diameter i can get a few feet of it prior to disassembly. Its 45 minutes to any parts store around here.

I’ll get that for you TacticalAnt when the wife gets back from her eyelash appointment. Maybe 2 hours tops.

Have a good one
-Bryan

Thanks, Are you measuring off the vehicle?. Would it be the same diameter as the OD of the steel tube it connects to?

Hey buddy.

On hers the OD of the front hoses are 1” and the ID is something between .625 and .700. Not easy to get to. I’d look at 3/4

The rear are .700 OD and 1/2 ID.

So 3/4 is .750”, that would be too big. 18mm converts to .708, thats in line with your .700 measurement.

Hello

Here, heater hose is metric (more or less) and I’d expect the fittings to be metric (more or less) but lots of hose is measured in non-metric measurements and lots of hose, plumbing and other fluid areas are non-metric.

Also here, heater hose is to ‘SAE J20 R3’.

If you take a look here:
https://jarukindustries.co.uk/products/heater-hose-sae-j20r3-choose-length-size?variant=20656950640751
you’ll see the site lists 4 sizes of hose with ‘size’ and ‘id x od’ measurements.

When I’ve been replacing hose I’ve used 13 x 20 (1/2”) and 16 x 23 (5/8”).

The fittings on the front matrix are 17mm. Here’s mine after refurb:


The larger in this picture (the ‘L-375’ is fine).


This is actually 15 x 22. Seems different manufacturers have slightly different dimensions.

Heater hose is fairly easy to expand a bit by dipping an end in hot water and using a bit of suitable grease. It's also designed not to collapse when bending, but I’d say don’t cut the piece too long if you’re not using OEM to limit the chance of it creasing.

I’m not a big fan of the windup hose clips, but mine have all been good. It’s just that they are hard to reuse once disturbed. I’d replace with A2 stainless steel Jubilee clips or the spring-loaded types. While seemingly not as secure the latter have the benefit of providing constant clamping as the hose is squeezed over time and can’t be over tightened. They do need to come in more size variants though.

HTH!

@LH119V, are you saying the steel pipes in the box measure 17mm OD, and the hose your using (L-375) measures 15mm ID? And that will fit with a little hot water and persuasion?
On the topic of hose clamps. Im seriously considering the Gates PowerGrip SB. They are a heat shrink type. At first I thought, no way, but the engineering test in the video convinced me.

Yep.

Those power grip clamps are amazing. If you can find them in stock highly recommend