I want to replace my radiator cap. I went to the local Ford Dealership and they were unable to tell me what the proper cap is. I have a 1995 F-350 CC with a 7.3 DI 4x4. The current cap says it is a 6.5 kpa, I don't know that this is the original/correct cap. A part number or pounds would be great.

 

I believe it's a 16lb cap.

Dealerships are a joke sometimes when it comes to finding even simple parts. I'd try napa or car quest if you have one by, they may be able to help.

 

Thanks, that is what the Dealership told me. They were trying to sell me a 16 lbs. cap, but their computer said it was for a 1994. They had no information for a 1995 and I didn't want to take a chance.

If it is a 16 lbs., that is equal to 110 kpa. and I have a 65 kpa. on it now. Maybe that is why it is leaking more than it should.

 

Is it leaking at the cap? That would be strange as it would have to be really full of fluid. If it is leaking somewhere else then a cap that creates more pressure should create a bigger leak.

 

X2

Just to be clear we are talking about the cap on the surge tank right?

I believe if you have an IDI the cap is still on the radiator, where as our trucks have it on the surge tank (no cap on the radiator). Without any info in your signature its hard to tell.

Not trying to be difficult just want to point you in the right direction!

 

It is the cap on the radiator, not the surge tank. The surge tank has a little slip on cap.

VIN#: 1FTJW36F7SEA12250

It is a Ford F-350 7.3 Power Stroke Diesel, OBS.

One poster mention that he thought it would leak more with a higher pound cap, I don't see how, with a higher pound cap it would take more pressure before it open to allow excess pressure to escape into the surge tank.

 

I stand corrected, they must have changed them at some point. Cause my 97 has a pressurized surge tank with no cap on the radiator. I just assumed they changed them when they went to the Powerstroke in 94.5. I'll do some checking here myself and see what I come up with.

 

I don't know that you are wrong. It could have been changed before I bought it. As I said, the Ford Dealership couldn't find a part for it, they did show me a parts diagram of the type of system you are talking about. We were using my VIN#.

I am skeptical about using a 16 lbs. cap, even my Peterbilt 387 with a Cat. C15 with over 500 HP only uses an 8 lbs. cap. I don't want to create excessive pressure and have my radiator develop a leak.

 

The '94.5s and EARLY (like, before mid January mfr. date) '95s had the old-style radiator with the cap on the radiator tank and the "overflow" bottle, rather than the degas bottle found in the later '95s up to '97. That's why the listing at the dealer only refers to the '94. Since you have the old-style cooling system, the '94 reference would apply to your truck as well.

 

OK, thanks. I wonder why the dealership couldn't tell me this?

So, the 65 kpa. cap on it now is slightly more than half the pound rating it should be, no wonder it is leaking!

 

Pretty sure the early powerstrokes with a radiator cap / overflow tank opposed to a degas bottle were 13 PSI. Stant 10329 seems to fit the bill.

On edit: Just a thought. I have no idea for sure. Might the 13 PSI cap be based on the fact the early Powerstrokes had the 205* thermostat?

 

Yeah, you are right. I wasn't thinking it had the cap on the actual radiator. Is it running hot at all or just leaking at the cap? If it isn't running hot then you might go with the lower cap just to give yourself a better safety vavle? Just thinking out loud. The pressure does change the boiling point to the fluid, though. Something to consider.

 

It was leaking badly at the water pump and the water pump cap. When I took the water pump cap off along with the top hose to the radiator, I didn't see a gasket. The rubber ring on top of the thermostat was stuck to the bottom of the cap, there wasn't a bottom rubber ring on the old thermostat. I cleaned everything up and installed a new thermostat. The dealership sold me an O ring as a gasket. I'm not sure where it goes. I put the thermostat in first then put the O ring on top of it, then placed the cap on top of that and tightened it down with the three bolts. It still leaks, but not as bad. I will replace the water pump cap and make sure everything is centered and tighten the bolts down tight. That O ring bothers me!

 

Read this link:
https://www.ford-trucks.com/forums/1...my-95-psd.html

The o-ring for the thermostat has to be square type, not round, IMHO how is yours?

 

Are you referring to the thermostat housing? The flange is probably warped/bent. You need one of these: Thermostat Housing Ring