Philbert

iTrader: (2)

Hi guys,

As I continue to try to troubleshoot my cooling system demons, I want to try to looks for leaks, as well as test my cap (which is newer....).

Someone lent me this kit (but no instructions - and I can't find them online):

http://www.matcotools.com/Catalog/to...&page=2&#38207


The gauge has several PSI ratings on it.

Can anyone help me understand how best to use this thing? I feel like I read last night online that the "normal PSI rating for the 22RE is 14...so would I pump the gauge to 14 PSI, and then look for leaks? Is the cap supposed to "give" at this PSI and start to let out excess into the extra coolant tank next to the radiator?

I also plan to test out the T stat, but want to start here.

Thanks in advance!

wyoming9

iTrader: (1)

First you need to be sure the correct adapter is on and screw it on your radiator pump the pressure up to about 13 pounds or so. see if it holds pressure.

If it doesn`t the leak should be easy to spot unless it is the head gasket or heater core

Testing the cap is a little different and I am not sure quite how to test them without looking closer. They are so cheap I just replace them.

Philbert

iTrader: (2)

Thanks!

That's what I was thinking - just needed to know the appropriate PSI setting.

So, in theory, if it holds at 13 PSI, and I then crank the pressure higher, the (properly functioning) radiator cap would then release the excess pressure into the overflow jug, right?

For the cap, there is an adapter in the kit I believe - I think I'll just hook it up, and crank it to 13-15 PSI and see if the cap "reacts"....

zlathim

Unless your tester is different from any of the ones I've used, the answer to your question about the cap relieving the pressure is no.

You will attach the tester to the radiator in place of the cap. Pump up the system to the desired psi, then let it sit to see if there is a leak. If it is leaking, coolant will either be streaming out onto the ground, or leaking internally in the engine. If it is not leaking, it will hold at pressure for at least 10 minutes. ( don't quote me on the exact time, but if it is leaking, it is usually pretty apparent ).

The cap is tested seperately using an adapter that should be in the kit. You hook the pressure guage and cap to opposite ends of the adapter, then pump it up to just below the pressure rating of the cap. If it leaks it is junk. If it passes, then pump it up to see what pressure the cap releases at. If the pressure exceeds the rating of the cap, it is junk. If not it is good.

Hope this helps.

4Crawler

iTrader: (3)

Cap pressure is usually stamped on the cap as well. Also, you can leave the pressure tester on the radiator and run the engine and see if there is any pressure change with the engine running. If you see the cooling system pressure rise and fall w/ engine RPM changes, there may be a combustion chamber to cooling system leak that causes the system pressure to rise.

Philbert

iTrader: (2)

Thanks everyone - this is great information! I'll report back this weekend on results.

Phil

Philbert

iTrader: (2)

OK guys - got to doing this over the weekend and here are the results.


Tested the pressure at cold, and, at 13 PSI, noticed a small leak with the top hose. I have a GlowShift temp sender adapter that slots in between the hose (you need to cut the upper hose to accommodate) - this was leaking. I tightened up the clamp, re tested, and it held at 13-14 PSI for about 10 minutes - no loss of pressure.

I did NOT have the cap tester adapter, so I skipped that part.

The hose to the overfill tank was clear - I "blow tested" it - sure that's safe....

So I bought a new OEM cap and T stat from the dealer. I asked about teh dual stage T stat but they said only ONE was available...it's not dual stage :/ I replaced the T stat and cap, refilled, and ran with the cap open for about 10 minutes before putting the cap back on. NOTE: before this, I hooked up the pressure guage again - it held at 13 PSI, but when I revved the throttle, it dropped to about 12 PSI. It went back to 13 when I let off throttle. 4Crawler - I think this ties into what you said....long term leak over time - not dire?

Anyway, so I drove it around town for about 25 minutes and the Autometer gauge stayed mostly around 150. At some point it finally went to 180 or so. Then it went to about 195....never really going higher than this. Is this normal? I'm paranoid about this, as the engine seems to cycle through different temperature cycles...I thought that it was supposed to stay at 180 once the T stat opened, and that was the "normal" operating temperature? Please clue me in if I'm off my rocker here?

I also tested the previous T stat in a saucepan on my stove....it opened, but around 190-195 instead of 180 - and it was stamped 180. Broken?

And lastly, I got another top radiator hose, as I was hoping to relocate the 1/8" NPT sender for my coolant temp to the T stat housing. I went to the hardware store, shopping for a tap for teh sender, but the guy helping me looked at my housing and recommended against it - said the walls were too thin and that there would not be much thread for the sender to catch. Is there another, good place to tap into the coolant system with the 1/8" NPT fitting? I want to keep my OEM sender, since I have the SR5 cluster.

Thanks guys - just trying to close this issue out - I am paranoid about this cooling system....

snobdds

Stock t-stats are rated for 195* F. - 88* C. So it looks like your t-stat is working fine.

Philbert

iTrader: (2)

Thanks snobdds - the previous one I'd had was rated at 180* - but it was from Kragen....hmmmm.

Regarding the cooling temperature cycle, however - is that normal for it to "cycle" between ~150-180-195, as long as it doesn't really go much above 195*?

As mentioned, I'm paranoid about this now, and can't stop watching the Autometer gauge while driving.

And, for anyone else just now tuning in, I'd love to get recommendations on where best to tap my 1/8" NPT sender for the gauge (other than my T stat housing)?

Thanks guys.

4Crawler

iTrader: (3)

I think a slight pressure drop with higher revs is normal (Bernoulli principle). But a pressure RISE with higher RPMs is not good.

For the sender, see if you can locate a junkyard truck with turbo or automatic, as those will have t-stat housings with 2 or 3 ports on them. Or get a tee fitting for the existing port and hook up the stock fitting plus yours to that.

Philbert

iTrader: (2)

Thanks 4Crawler - I actually had gone to OSH this weekend with my T stat housing, looking also to do the T solution. The guy who helped me seemed to thing it was a 3/8" pipe fitting for the OEM sender, but could not be sure, without the actual sender...when threading in some standard pipe thread in the store, it didn't go all the way (pipe was tapered but he thought the t stat housing hole was the same diameter the whole way through....anyone ever done a T setup and mind sharing what they used to create it?

And 4Crawler, it didn't go up in pressure, just down, so that's good

4Crawler

iTrader: (3)

Sender is likely M10-1.0 or 1/8"BSP thread:
- http://www.4crawler.com/4x4/CheapTri...html#Breathers

Auto parts stores should have a sender adapter kit with all sorts of adapters for various thread etc. to install gauge senders:
- http://www.egauges.com/vdo_send.asp?...apter_Bushings

Philbert

iTrader: (2)

Thanks Crawler - great stuff! I never get tired of reading your site and I always wonder how I miss things on it from the past

Philbert

iTrader: (2)

Here is a dumb question.....

The OEM sender unit sticks down into the T stat housing, seemoingly into the coolant flow, as it gushes past the T stat and into the upper radiator hose.

SO, if you were to create a T connection from that location for the OEM and aftermarket senders, how would they measure coolant temp if they were then suspended well above the T stat housing and neither one dipping into the coolant flow?

Is coolant running *so much* through the t stat housing that it will flow up and into the T housing with the 2 senders?

4Crawler

iTrader: (3)

Probably won't respond as fast but heat will conduct through the coolant and make the coolant inside the tee, and the metal of the fittings all reach the same temperature. Of course, not as quick as the convective heat transfer of the flowing coolant.