Should the radiator cap be 18 psi?

18 PSI sure is a lot of pressure. Maybe at the root of heater cores and radiators springing so many leaks. I replaced mine with a 13 psi cap. I am watching it closely . No problems .
 
How long ago did you do that?— Thats a big jump / drop from 18 to 13. I think the engineers know best but maybe you should have dropped a couple 2-3 pound IF you wanted to experiment.
 
I’ve got everything ordered except a heater core. I’m praying this rejuvenated cooling system with an 18 psi cap doesn’t blow the heater core out.
 
Are you having any issues with your cooling system? Do you hear it gurgle when you shut it off hot? Are you losing coolant without leaking?
I’m losing coolant. Bout a gallon a day. My Jeep don’t have the reservoir for it But I don’t see no leakage. Maybe lil outta the overflow tube Any suggestions?
 
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I’m losing coolant. Bout a gallon a day. My Jeep don’t have the reservoir for it But I don’t see no leakage. Maybe lil outta the overflow tube Any suggestions?
Seeing no leakage under the Jeep and losing that much coolant makes me think blown head gasket which sends the coolant out the exhaust whenever the engine is running. Use a 'sniffer' strip in the top of your radiator to sniff/detect exhaust gases which will pretty much confirm it.
 
I get a discount at the dealership,from being in the auto business and when I did my system all o/e,it HURT to buy the cap,my cost was 28 bucks geez!
Most dealers gouge customers every chance they get, especially in the parts and service departments that provide, literally, most of the income and profit for a dealership. I don't buy parts from dealers very often due to their costs but sometimes they're the only game in town when you need a Mopar part NOW. But for a radiator cap? I'd have gone straight to NAPA. :)
 
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Most dealers gouge customers every chance they get, especially in the parts and service departments that provide, literally, most of the income and profit for a dealership. I don't buy parts from dealers very often due to their costs but sometimes they're the only game in town when you need a Mopar part NOW. But for a radiator cap? I'd have gone straight to NAPA. :)
Ya my cost on the water pump kit was 126.00,oh well
 
That's actually not bad for a Mopar in today's market!
Hey,I got my Dana 44 in and was adjusting the brake and was surprised to see that the tires are spinning opposite on my Detroit Lsd .I just about crapped myself,lol.I saw your very old post and felt better

8556BE11-3805-4F77-8A0C-8924A78EE6D5.png
 
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Hey,I got my Dana 44 in and was adjusting the brake and was surprised to see that the tires are spinning opposite on my Detroit Lsd .I just about crapped myself,lol.I saw your very old post and felt better

View attachment 286917
Hey,I got my Dana 44 in and was adjusting the brake and was surprised to see that the tires are spinning opposite on my Detroit Lsd .I just about crapped myself,lol.I saw your very old post and felt better

View attachment 286917
@Jerry Bransford,You’re an old forum legend
 
In gearing up for my cooling system overhaul, the previous owner replaced everything with store parts;
Radiator
Water Pump
Radiator Hoses
Worm clamps
Thermostat
Radiator cap

While I applaud the effort and quality of work, I despise the quality of parts and here in the desert with the AC running I am getting the needle too far past the 210 dot than I’d like. This is my fifth TJ/LJ 4.0.

Just to correct a few things…

The radiator cap from the factory is TVS, Chevy uses them too, but 15psi. One feature I like is the ported vent, it doesn’t hold pressure till rapid expansion of the fluid. Basically doesn’t pressurize until needed. This I believe will help relieve the cooling system stress/leaks. Jeep used this style off and on over the years as well. So nothing crazy going on here.

I’ll be getting a mopar radiator and water pump, they’re the best, PROVEN… however I MAYYYYYYYY gamble with an all aluminum, 2x 1.25” row American made , fully welded radiator with pressed end tanks. This recipe has worked for corvettes for years and one prideful company gladly overcharges for the same construction. Corvette guys will know who I am talking about, but they work very well.

THROWING THE WORM CLAMPS AS FAR AS I CAN!!!! I always buy/upgrade/replace all worm clamps with factory style spring clamps on all my cars/trucks/Jeeps from bel metric. They’re made by the same company as the factory MUBEA, so when our clamps say MU26, for example, it refers to a Mubea clamp with a 27mm nominal diameter …

Thermostats are all Motorad now, Stant, gates, mopar, they all have Motorad stamped on them… back in the day I got one and noticed fluctuations in the needle, plus they had plastic in their construction. I was able to get a STANT and been using them ever since with rock solid temperatures just below the 210. Now that is no longer an option, Motorad may be better now but I’m gonna try an edelbrock universal thermostat, 54mm 190 degree that’s made in USA. Flowkooler says their thermostats are robertshaw but not willing to gamble that they’re not the same as the mr gasket knockoffs, I haven’t had success with those. Original Robert Shaw thermostats seemed to work, I had a few older cars with them installed, I just put them back in when I was doing cooling system overhauls.


Take this from a desert boy, whatever they used at the factory was enough for a bone stock 98 TJ with 33” tires, 4” lift to NEVER go over 210 with AC so cold I had to turn it down on hot summer days … Jeep did good, but our parts are drying up. It’s either cheap replacement parts or over priced “upgrades”, both are not ideal … but someone needs to experiment before mopar shuts us down.
 
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In gearing up for my cooling system overhaul
I'd do a chemical flush first if you can. Thermocure or Prestone or both before you dive into parts. Get the thermostat and housing gasket so the job is easier. Spring clamps are a great idea along with new hoses after you get the system cleaned out. I'd forget all that other stuff unless you have problems after the flush.
 
I'd do a chemical flush first if you can. Thermocure or Prestone or both before you dive into parts. Get the thermostat and housing gasket so the job is easier. Spring clamps are a great idea along with new hoses after you get the system cleaned out. I'd forget all that other stuff unless you have problems after the flush.

The jeep is new to me, the radiator is new and the coolant is perfectly clear, no residue anywhere and bottle has no debris. I suspect the cooling system was well kept and/or flushed before I got it. I have had a sting dose of RMI-25. No residue yet.

In case you don’t know, RMI25 causes all the rust and contaminants to float to the top and eventually make it to the recovery bottle.

But I’ll be doing a strong flush before I take it all apart and replace it all …