Jump to content

Cooling system leak?


Recommended Posts

OK I have been driving my MJ for a little over two months and everything is fine up until recently. The truck is leaking coolant when it is hot at the resevior. It seems to be leaking where the hose goes in the side of the tank. I have tried tightening the hose clamp and that doesnt seem to help. The truck is not running hot, always stays right below 210. After 22 years it could just be that the hose is deteriorated and needs to be replaced. I looked at it quickly this morning as I was leaving fo work and it looks like it will been to be purchased as a until because there it a t in the hose that has crimp fittings. Guess it would help to let you all know this is a closed cooling system in an 88MJ. Beofre I go out and buy the hose and spend the time changing it out I am wondering it anyone has any other idea as to what I might be or is it just a leaking hose. I am assuming that this system must vent pressure some how, could it be the vent is stuck and it is building too much pressure? Assuming there is a vent on the tank where is it? Is it in the cap like on an open system or somewhere else. I don't have time to be messing with this right now so I want to be sure I get it right the first time. Can anyone help?

Link to comment
Share on other sites

The bottle is "reinforced" at the connections with some metal tubing (on the inside). These things are so prone to overpressurizing and cracking it's reedonkulous. The bottle is THE weak point in the system. short of converting your rig to an open system you likely need a new bottle and cap. As far as the hoses with the crimp on's I cut the fitting off lengthwise and just replaced it with regular hose & clamps.

Link to comment
Share on other sites

OK so if this bottle is the weak link in the system and is more than likely the problem what can be done to address it. Since it was suggested that I look at ebay for a tank it would seem to me that they are no longer available new. Has anyone come up with a better replacement? Or do most people just swap to an open system? This is the route I am planning on going when I have more time, right now I just need to fix this or keep adding water.

Link to comment
Share on other sites

I just purchased one of these http://www.macsradiator.com/replacmentjeepradiatorfilltanks.aspx, a little pricey (could get five stock plastic ones from Quadratech http://www.quadratec.com/advisor/jeep_oem_replacement_parts/cooling/cooling_bottle.php for the same price), but I got tired of the cracking bottle and the bad cap seals.

Link to comment
Share on other sites

:agree: I, too have an aluminum surge tank on the way. I've replaced the plastic tank at least three times because of fissures or cracks and coolant loss. Been through a couple of factory tanks as well as aftermarket types. This latest one, a Dorman from Rock Auto, is kaput after six months. I'm done with the plastic. To answer your question about system pressure management, the black plastic cap is a pressure cap that works essentially like a regular radiator cap, and is calibrated to maintain 16-18 psi in the system.

Link to comment
Share on other sites

Thanks you everyone for your input. It got really bad this morning and what I though was a leaking hose is a crack in the tank near the hose nipple. I had to leave the truck at home and drive my ZJ.

 

I just ordered the plastic tank from Quadratec. They are in Pennsylvania and I should have it tomorrow. I would have probably sprung for the Aluminum tank but I need to tomorrow and I am planning on swapping in an open system. If that doesnt happen next time I need a tank I will get the aluminum one, that thing is sweet.

 

Thanks again for everyone help.

Link to comment
Share on other sites

The Macs tank uses a standard radiator cap. There is a hose fitting in the filler neck for the cap. If you run a hose from that fitting to an expansion tank (not an overflow tank) you will have an open system. Its that easy.

 

An expansion tank from an early MJ with a 2.5L works perfect for this mod.

 

Link to comment
Share on other sites

The Macs tank uses a standard radiator cap. There is a hose fitting in the filler neck for the cap. If you run a hose from that fitting to an expansion tank (not an overflow tank) you will have an open system. Its that easy.

 

An expansion tank from an early MJ with a 2.5L works perfect for this mod.

 

 

 

That is a killer setup....when the new expansion tank cracks, which I know it will, this is what I will be doing and skipping the open system swap. Thanks for the information.

Link to comment
Share on other sites

Glad I could help. I have had a lot of problems with the plastic tanks. Not only do they crack but the caps don't seal very well either. I had a hose clamp around the cap for a while. Got tired of the whole set up. With the metal tank you can fix it right and move on.

 

Also when you purge the system removing the temp. sender at the back of the head is a great way to do it. Don't forget to do that.

 

Here is a picture of the 2.5L expansion bottle. You can get cheaper universal ones at any auto parts store, but I really like the way this factory one worked out. It bolts right up to holes that are already in the inner fender. You also have to order the cap separatly. I don't have the part # any more but some one on this site gave them to me.

 

This set up also allows you to keep your electric fan sensor or add one if you don't have already have it.

 

Good Luck. :cheers:

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...