Anything Special About Our Radiator Caps?

[TurboDiverArt]

Hey all,

Simple question. Anything special about our radiator caps on the reservoir? Can I just get a new one at NAPA? Although I think I really know the cause I'm hoping that I may have a weak radiator cap after 200K miles and that's the cause of my coolant loss. I'm losing about a gallon of coolant every 3000-miles. I never had that happen for about 80K but for the last 5000-6000 miles I've had the low coolant light come on where I needed to add close to a gallon both times. Although it's a very good possibility it's a head-gasket at 200K I'm hoping it's something simple like a radiator cap or leaking line somewhere. I haven't inspected the hoses closely yet.

I get no smoke when driving, stepping on it or at start-up other than the usual little puff on cold start-up.

Art.

[DA BIG ONE]

I would check heater hoses carefully especially at plastic "T"'s t's can crack too, then hose between pump and t-stat housing. I had to change out both t's, heater hoses, rad hoses and hose between t-stat housing and water pump. Sub-tropics take a toll on hoses.....................

[TurboDiverArt]

I would check heater hoses carefully especially at plastic "T"'s t's can crack too, then hose between pump and t-stat housing. I had to change out both t's, heater hoses, rad hoses and hose between t-stat housing and water pump. Sub-tropics take a toll on hoses.....................
Funny you should say that...

Happily I can announce that the coolant leak is external to the engine. I have small puddles that form under the passenger side of the truck. No it's not A/C water cause it's sweet like antifreeze. While having the truck idle I watched for drips. The drips are running down my down pipe. With the quick look I took I can see the drips go up at least as far as where the down pipe and the cross over come close to each other. I was thinking either a cracked reservoir or one of the many heater hoses that run in that area including those pesky Tee's. I just don't want it to be one of those damn rear heater lines. I had to replace the ones running to the rear A/C 2 years ago and they are pretty expensive! I'll need to spend more time, maybe tomorrow, and inspect the easily accessible lines up top. Probably pulling off the turbo shield will give a better view downward. If that doesn

[DA BIG ONE]

A weak cap or broken cap gasket will allow overflow, think overfilled maybe? I know I've overfilled my res/rad many times! Did you also open the top vent at stat housing to allow air to bleed, or?

[TurboDiverArt]

A weak cap or broken cap gasket will allow overflow, think overfilled maybe? I know I've overfilled my res/rad many times! Did you also open the top vent at stat housing to allow air to bleed, or?
Yeah, I bleed air out of the therm housing routinely since I run Dex-cool.

I don't think I'm overfilling it as eventually the "low coolant" light comes on and I have to add more.

I looked at the end of the overflow hose when it was dripping down my downpipe last night and it appeared to be dry so I don't think that's the source. I

[DA BIG ONE]

Got my t's from GM & only come w/heater hose to core............

[TurboDiverArt]

Got my t's from GM & only come w/heater hose to core............
I was thinking that I would get brass T's from a plumbing supply place. Maybe GM is the way to go. If it's the T's and I got 200K out of the last set then maybe brass is overkill....

Art.

[DA BIG ONE]

I was thinking that I would get brass T's from a plumbing supply place. Maybe GM is the way to go. If it's the T's and I got 200K out of the last set then maybe brass is overkill....

Art.

Art, those core hoses are a PITA to change out but needed...........

[TurboDiverArt]

Art, those core hoses are a PITA to change out but needed...........
Any easier to get at with the reservoir out and turbo shield off?

Art.

[tommac95]

I experienced intermittent coolant loss , no obvious leak ... then
>was dripping down my downpipe
The cause was found to be clamps on heater core tube at firewall ; pretty easy access [if clamps good orientration] with reservoir removed.

I made a note to replace with spring-hose clamps if i get a chance....

[TurboDiverArt]

I experienced intermittent coolant loss , no obvious leak ... then
>was dripping down my downpipe
The cause was found to be clamps on heater core tube at firewall ; pretty easy access [if clamps good orientration] with reservoir removed.

I made a note to replace with spring-hose clamps if i get a chance....
It's possible that's the problem. I checked the plastic T's on top of the valve cover. They are dry. I see no coolant dripping down the fender well from the reservoir feed hose. If I look in through the wheel opening I can see the downpipe through the opening. The downpipe is wet at that point.

From the engine compartment I can see the two heater core inlets. With the reservoir and turbo shield in place I can't get a really good look at the heater core so not sure if they are dripping from underneath. I can see where the rubber hoses off the T's transition to what I believe are the hard lines running to the rear heater. They appear to be dry but until I can actually get a hand on them I wont know for sure. It was too hot to really spend too much time hanging over a hot engine. It was like 95-degrees and 100% humidity today so I only took a quick look. Hopefully it'll cool down some so I can really figure it out.

Since I don't think the leak is from the top hoses or the T's, I'm not sure what other lines run down the firewall in that area. I figure 2 for the heater core and 2 for the rear heater unit. Any other hoses/tubes that run down the firewall?

Art.

[tommac95]

>Any other hoses/tubes that run down the firewall?

My primitive pickup only has one (forward) heaterbox....

[TurboDiverArt]

I would check heater hoses carefully especially at plastic "T"'s t's can crack too, then hose between pump and t-stat housing. I had to change out both t's, heater hoses, rad hoses and hose between t-stat housing and water pump. Sub-tropics take a toll on hoses.....................
OK, I take that back! I checked very carefully, this time when the truck was hot. I'm seeping water from where the heater hose meets the "T". Are these T's anything special or can I get them at NAPA? I'd like to fix it this weekend and the GM parts counters are closed on the weekend. If they are some special GM "T" then I'll have no choice but to go next week and try to stretch it another week.

I don't think it's the hose because I can feel anti-freeze under the "T" as well as at the edge of the hose and all the way down it on the underside.

I guess I could replace the factory hose clamp with a constriction style but I've really never had a problem with the GM style clamps so I'm not thinking that is the real cause.

Any thoughts?
Art.

[TurboDiverArt]

OK, I take that back! I checked very carefully, this time when the truck was hot. I'm seeping water from where the heater hose meets the "T". Are these T's anything special or can I get them at NAPA? I'd like to fix it this weekend and the GM parts counters are closed on the weekend. If they are some special GM "T" then I'll have no choice but to go next week and try to stretch it another week.

I don't think it's the hose because I can feel anti-freeze under the "T" as well as at the edge of the hose and all the way down it on the underside.

I guess I could replace the factory hose clamp with a constriction style but I've really never had a problem with the GM style clamps so I'm not thinking that is the real cause.

Any thoughts?
Art.
Da Big One,

You don't happen to have a part number for the "T

[DA BIG ONE]

GM part # 15979269 list $25.65 ea., net $19.89 ea., they only come assembled heater hose to core w/tee and new spring clamps. Get 2 and change em out together, or soon you'll be doing it again...........

[TurboDiverArt]

GM part # 15979269 list $25.65 ea., net $19.89 ea., they only come assembled heater hose to core w/tee and new spring clamps. Get 2 and change em out together, or soon you'll be doing it again...........
OK, thanks a lot! At first I was like $25 for a plastic "T" then I realized it came with the core hose. Still a lot for what you get but not as bad as I thought. I'll have to pick up a pair of them. Thanks again for the part number!

Art.

[TurboDiverArt]

GM part # 15979269 list $25.65 ea., net $19.89 ea., they only come assembled heater hose to core w/tee and new spring clamps. Get 2 and change em out together, or soon you'll be doing it again...........
I checked GM Parts Direct and that part number appears to be the hose only, list price $19.89. I also stopped by the NAPA warehouse and that number is a hose only. I'll need to stop by a GM dealer next week to get it. I was hoping to get it through GM Part Direct so I don't need to go to a dealer, it's just easier.

http://www.gmpartsdirect.com/results.cfm

Art.