Pressure Test New Radiator before Install?
#16
CF Veteran
Thread Starter
Join Date: Aug 2019
Location: East Tennessee
Posts: 1,578
Received 217 Likes
on
185 Posts
Year: 1996
Model: Cherokee (XJ)
Engine: 242 cui
![Default](https://www.cherokeeforum.com/images/icons/icon1.gif)
If you are going to keep the Jeep for awhile, take a look at my profile. In the profile under Misc Accessories is my slow build on another forum. You'll see what I did for silicon radiator hoses & heater hoses. Since the front end was apart, I also installed a transmission cooler.
In the near future, I'll be pulling the dash to rebuild the heater control box, install an ALL METAL heater core, and a new evaporator core.
In the near future, I'll be pulling the dash to rebuild the heater control box, install an ALL METAL heater core, and a new evaporator core.
#17
Seasoned Member
Join Date: Sep 2019
Location: Around the world
Posts: 328
Likes: 0
Received 93 Likes
on
78 Posts
Year: 2001 / 1999
Model: Cherokee (XJ)
Engine: Fire breathing 4 point Oh!!!
![Default](https://www.cherokeeforum.com/images/icons/icon1.gif)
I've bought heater hoses in bulk from diesel truck repair places. I believe the ones you see on my Jeep came from eBay. Just so you know, the In / Out on the heater core are slightly different sized. Obviously, the larger sized will have to be coaxed on. I think I used a little bit of soap to help it slide on.
The following users liked this post:
318SixPack (11-02-2019)
#18
CF Veteran
Thread Starter
Join Date: Aug 2019
Location: East Tennessee
Posts: 1,578
Received 217 Likes
on
185 Posts
Year: 1996
Model: Cherokee (XJ)
Engine: 242 cui
![Default](https://www.cherokeeforum.com/images/icons/icon1.gif)
I've bought heater hoses in bulk from diesel truck repair places. I believe the ones you see on my Jeep came from eBay. Just so you know, the In / Out on the heater core are slightly different sized. Obviously, the larger sized will have to be coaxed on. I think I used a little bit of soap to help it slide on.
However, I am hesitant to try that with a pressured line of any kind especially one with great temp swings like a coolant/heater line. Not a fan of stretching it onto a part that is too big for the intended diameter of the hose either.
The bigger wonder is why the Hell they do it this way. Every fitting that uses heater hose could be the same size, but they aren't. Every fitting that uses vacuum could have the same size fitting on the manifold and on the part, but they don't. And it sure is not an issue to get you back to the dealer to buy parts, because it is well demonstrated that anybody who makes parts can make them this way too.
Edit: As soon as I posted that I adjusted my search strategy and found these things exist in multiple sizes:
https://www.autozone.com/fittings-an...tor/102831_0_0
My latest problem for next springs projects is solved, and now the clamp requirement has doubled.
Last edited by 318SixPack; 11-02-2019 at 09:27 AM. Reason: New info
#19
Seasoned Member
Join Date: Sep 2019
Location: Around the world
Posts: 328
Likes: 0
Received 93 Likes
on
78 Posts
Year: 2001 / 1999
Model: Cherokee (XJ)
Engine: Fire breathing 4 point Oh!!!
![Default](https://www.cherokeeforum.com/images/icons/icon1.gif)
The bigger wonder is why the Hell they do it this way. Every fitting that uses heater hose could be the same size, but they aren't. Every fitting that uses vacuum could have the same size fitting on the manifold and on the part, but they don't. And it sure is not an issue to get you back to the dealer to buy parts, because it is well demonstrated that anybody who makes parts can make them this way too.
Hot liquid that has expanded goes in (big tube). Heat is removed (heater core / radiator) temperature drops, pressure drops. This would create a vacuum / cavitation. In order to keep the pressure up, the exit hose needs to be slightly smaller. This probably isn't the best explanation, or using the right words, but I think you get the idea as to why hoses are different sizes.
#21
CF Veteran
Thread Starter
Join Date: Aug 2019
Location: East Tennessee
Posts: 1,578
Received 217 Likes
on
185 Posts
Year: 1996
Model: Cherokee (XJ)
Engine: 242 cui
![Default](https://www.cherokeeforum.com/images/icons/icon1.gif)
The hoses from the thermostat to the heater valve are big at the thermostat housing end, and smaller at the heater valve end. Then the hoses leaving the heater valve are small, but the ID gets big again at the heater core line. If this were some sort of velocity issue then the valve needs high velocity coolant going in to work but the heater core needs lower velocity? Not adding up that the vacuum operated valve needs a wee slight pressure tweak by necking a line down 1/32" or so.
Last edited by 318SixPack; 11-03-2019 at 08:39 AM.
Thread
Thread Starter
Forum
Replies
Last Post
ebranch
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
19
05-04-2015 11:41 AM
Dragon01
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
12
04-20-2015 07:32 PM
freegdr
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
116
01-07-2014 07:39 PM
bear2bear71
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
1
04-07-2012 09:33 PM
BotakBeng
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
6
10-19-2011 09:02 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)