• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

heater hose sizes

O

outlander

NAXJA Forum User
Location
Columbus,Ohio
I've deleted the green turtle and heater valves and am running straight heater hoses from the core to the motor on my 89 xj 4.0.
My problem is 5/8 heater hose is too small for the upper heater bung and the tstat housing.
3/4 is too big.
I know you guys have been down this road before,so what did you do?
I tried dipping the end of the hose in boiling water but it would only go on about a half inch and will prob blow off....I don't want to keep pushing on the heater core bung for fear that it will start leaking and I do not want to tear my dash open for a transplant
 
Brass barbed hose fitting--5/8 on one end, 3/4 on the other, use the correct size hose on both ends, problem solved.
 
The problem is 3/4 would be fine for the tstat housing but the top heater bung is flared out on the end then necks down to I guess 5/8 so 3/4 there would be too big but 5/8 seems too small....make sense?
Do they make a hose that's in between 5/8 and 3/4?
 
11/32" is what mine uses, the other is 5/8"
 
Most times heating is enough, but friction is actually the problem. A little dab of silicon grease really makes it a lot easier. It also makes taking it apart years later a lot easier.

Get a tube at Home Depot around $7, the kind with PTFE (teflon), read the label and make sure it is plastic and rubber neutral, most are. It is likely to be in the plumbing section, maybe the automotive section.

It is also a really good rubber preservative for stuff you want to keep on the shelves for years.

Pretty much standard procedure for installing O rings. it allows then to slip and seat properly.

I use it sparingly and a tube lasts for years. Silicon grease and Copper paste, two things every shop needs.
 
8Mud said:
Most times heating is enough, but friction is actually the problem. A little dab of silicon grease really makes it a lot easier. It also makes taking it apart years later a lot easier.

Get a tube at Home Depot around $7, the kind with PTFE (teflon), read the label and make sure it is plastic and rubber neutral, most are. It is likely to be in the plumbing section, maybe the automotive section.

It is also a really good rubber preservative for stuff you want to keep on the shelves for years.

Pretty much standard procedure for installing O rings. it allows then to slip and seat properly.

I use it sparingly and a tube lasts for years. Silicon grease and Copper paste, two things every shop needs.
Click to expand...

Check around the faucet repair stuff - you can find a small tin of plumber's grease for a couple of bucks, and a that small tin is usually good until you lose it.

It's workable with elastomers and metals - I have been using it to lubricate stem seals, valve packing, and faucet washers & O-rings for 20 years or so, and it's not any problem.
 
One hose is 5/8" and the other is 11/16" (can't believe no one has said that yet :) ). But yes, you can get the 5/8" hose over the 11/16" fitting.
 
I'll just go into the parts store and tell them I want 11/16 ID heater hose......
(I wish it was that easy)
All these damn generic ass parts stores sell is 5/8 or 3/4 inch...
I'll check with napa and see if they can order 11/16
I tried forcing it over like I said in the first post but my but puckered up so I stopped pushing....hahahahaha
Thanks to all that replied
 
Last edited:
Last time I needed it, I got 11/16" hose from Pep Boys.
 
Some auto parts stores have ho's in different area codes...
They'll carry short bitch size peices in pre bagged lengths out in the customer part of the store, then they'll have a metal cart with 20 different kinds of hose in the back of the parts area thats sold by the foot, just ask.
 
Mercedes heater hose is 18MM, very slightly larger than 11/16". It may be listed somewhere and available in bulk (cut to length).
 
If it don't fit force it just use a little grease on the hose
 
I used vasoline on sockets 1 size at a time letting it sit in the sun to naturally stretch... I was in no hurry, could use heat gun or blow dryer if in a hurry.
 
Dunno - I redid most of my heater plumbing using 1/2" copper sweat anyhow.

5/8" fits neatly over 1/2" copper sweat tube. For the 3/4" junctions, I just soldered a 1/2" union over the 1/2" line - bam! instant 3/4" OD adapter!

If I did it again, I'd probably get a beading tool - but following double-clamp over smooth line had no leaks, and it solved the hassle of having to get hoses with moulded right-angle bends.

It also allowed me to add a backflush forcing valve and a hose Bibb adapter, which simplified maintenance. There are a couple of things I'd do differently, but it was a quick job (30-45 min, all up) done with materials on hand, so I can't complain too loudly...
 
Devilfrog said:
11/32" is what mine uses, the other is 5/8"
Click to expand...

umm ... yeah ... that should have read 11/16" ... oops.
But you already knew that by now.
Can pretty much get it in bulk at any parts store up here.
 
You must log in or register to reply here.

Similar threads

F
Advice from US Postal RHD owners - heater hoses
Replies
2
Views
2K
fenns7
F
tjmotter
Heater box repair - pics needed
Replies
1
Views
1K
75SV1
7
V
High temp woes
2
Replies
21
Views
397
Vitzaa
V
X
Replacing my entire cooling system
2
Replies
23
Views
4K
RCP Phx
R
R
Fan not turning on when hot- fan works!
Replies
2
Views
2K
JMA_2001XJ
J
Back
Top