Missing antifreeze, where could it be going?

[mickyd32]

First off, I'll say that I think I know where it's going, but I'm not 100% positive

Last season I installed a new SLP head on my 13. Things were good for the first couple hundred miles. But closer to the end of the season I noticed I was starting to lose level in the reservoir. I figure the rare at a couple ounces per tank. I'm 3 tanks of fuel or so my reservoir will go from appropriate level to empty.

So it's not major leak but it is going somewhere

The sled doesnt appear to smoke white at all, I also tried leaving the sled just sit and idle for 10 or so minutes in some fresh snow and no signs of antifreeze so I've ruled out an external leak


Where should I go next?

 

[sled_guy]

Coolant is clean? Check the outside of the cylinders below the head line to see if there is any discoloration/staining... as little as you are losing it might just be seeping out of the head and then evaporating off.

If the internal head o-ring is leaking then you will be blowing it out the overflow and the coolant will turn dark, getting dirty from combustion gasses.

If the coolant is clean then next thing would be a leak internally on the non-compression side (base gasket, water pump seal). Again, with as little as you are losing I wouldn't expect you to see white smoke. When my sled had a base gasket leak it never smoked white, but if I let it set for a few days, right after I started it I could smell the sweat smell of antifreeze in the exhaust fumes.

And it also cleaned the carbon off the one piston completely.

sled_guy

 

[geo]

Pistons is a good place to look if you are burning coolant. But your loss is small as you describe. So,,, I try to KISS when approaching mechanical issues first.

Cooling systems have been around for a while and it is checked by pressurizing the system and watching the gauge, then,,, look for a leak. An import car repair place should have the proper adaptor and tool for you and you might be able to give them a deposit and work on there lot.
First check cold (I always over-pressurize a bit. Hate being a whimp lol). Then check hot (careful, really,,, and clean up later) if needed.
If those simple first things to do don't show you the way, then you can make it complicated.

I had to do a lot of hand lapping to make my SLP head flat. Some say it makes no difference in such a thin casting but I just like things that are not too fancy, just flat.

 

[mickyd32]

Ok I do have a very good mechanic friend that builds race cars. He's likely got the tools for pressure testing the system. Problem is he just had a heart attack and I really don't want to bother him with doing the testing.

Can you walk me through how I pressure test the pro and I will do it myself?

 

[LoudHandle]

Another potential spot for leaks is around the head bolts. Most people fail to anneal the copper washers nor do they use and form of sealant.

To anneal the copper washers you must heat them to a dull red color and quench them in water. This is counter-intuitive to most people but that is how copper behaves. If you chose not to anneal and clean the washers and bolts, then be sure to use a sealant.

With the quantity of coolant loss you describe, a small weep from one headbolt may be all you have? When the engine is warm it is probably rapidly evaporated. Cold and no pressure in the system it may not weep, noticeably at least.

 

[NapaMatt]

Neighbor is coming over with a suction gun and taking ur antifreeze!!

haha lol!!

 

[mickyd32]

What pressure is good for texting. I don't gave a service manual. So I'm unsure what pressure the system runs at.
Do I go to like system pressure +10%? 25%?

 

[NapaMatt]

20 PSI is plenty!

 

[NapaMatt]

System normally runs at 14- 16 psi..

 

[mud99]

Last year I had a rock punch a hole in my heat exchanger, check under your tunnel for leaks. It might be completely unrelated to the head.

 

[89sandman]

Do you ever smell antifreeze? I'd say if you can't find a leak I'd pop the head off and and check the orings for signs of leakage.

 

[byeatts]

First off, I'll say that I think I know where it's going, but I'm not 100% positive

Last season I installed a new SLP head on my 13. Things were good for the first couple hundred miles. But closer to the end of the season I noticed I was starting to lose level in the reservoir. I figure the rare at a couple ounces per tank. I'm 3 tanks of fuel or so my reservoir will go from appropriate level to empty.

So it's not major leak but it is going somewhere

The sled doesnt appear to smoke white at all, I also tried leaving the sled just sit and idle for 10 or so minutes in some fresh snow and no signs of antifreeze so I've ruled out an external leak


Where should I go next?

If the O ring is leaking it will force the compression into the water system , Put a balloon over the reservoir overflow tube , under WOT and load it will inflate, Sure sign!

 

[NapaMatt]

If your in this far.. Don't Try and wipe the old O-rings .. on the head..

Have new ones ready to go. Easy fix.. Can turn bad in a hurry...

Q-Tips are your friend... EVERY Bolt hold must be dry!!! Less you want to send me money! hehe I do love selling HeliCoil Kits!!!

Try to drain coolant down before tearing in to it..

 

[jdw1]

I think I would check all of the hose clamps first, you might just have a "cold" water leak, if you haven't check yet anyway.

 

[geo]

MK32. Pressure check it if you can find-borrow-buy the tool. Hard thing to find will be the correct adaptor for our coolant bottle. All motorcycle, ATV, sled shops with mechanics should have one. Might not remember where it is because you use it so rarely now-a-days but when you do need it saves so much GUESS work.
I would even go to the effort of installing a 1" T or something in place of the coolant bottle or inline and check there if an adaptor could not be had. 8.991 times out of 10 the leak will occur at pressure below the coolant system design pressure. In-line T will also check coolant bottle (warped neck) and cap pressure (common failure in autos after a decade lol).

Simple procedure. Take off coolant cap, install adaptor (basically a coolant cap with out the pressure relief set-up and a fitting coming out the top), attach hose with pressure gauge and isolator valve, attach hand pump, pump it up lol ( I'd stop around 18 lbs) close valve and watch gauge.
9.359 times out of 10 the pressure cold will show the leak and the gauge will drop. Then check all external spots suggested and don't forget the waterpump seal weep hole. Keep pumping the pressure back to 18 and sooner or later you will leak out enough coolant it will stick out like a sore-sticky-sweet thumb.
If it don't lol, next is the combustion chamber. Chances are (8.625 times out of 10) if you couldn't find a leak externally it will be the head o-ring. Chances are, the time you spent pressurised to check external leaks will make just pulling the plugs and looking in enough to find the bad one but you may need to remove y-pipe or valves to look closer.
You'll be looking-tasting lol for coolant.

If you find an external leak quickly, fix it but don't claim success just yet, pressure up again. 1.614 times out of 10 there are multiple small leaks at this higher pressure from just clamps coming a bit loose-rubber getting old.

Hope it helps.

Really, this is the way to do it if you want to be sure.

 

[Super Dave3]

I think I would check all of the hose clamps first, you might just have a "cold" water leak, if you haven't check yet anyway.

X2 Every cyl head I have replaced has leaked at the fitting on the PTO side of the cyl head. Remove the spring clamp and replace it with a worm drive clamp.

 

[mike_s]

You dont need special tools to pressure test your cooling system, all you need is a rubber tipped air nozzle, and LOW pressure shop air. Your existing coolant reservoir cap has a check valve in it to allow air in, but not out. Put the cap on, and apply pressure to the reservoir vent line. You have to be very carefull though, as there is no pressure relief using this method. Also, be carefull when removing the lid to release the pressure, if there is air in the system somewhere, when you release the pressure coolant will spray everywhere...

 

[mickyd32]

Thanks for all the help guys. I was able to track down mechanic friend at his shop, never thought he would be there a week after having multiple heart attacks But he was

He has a tester, apparently it has a bladder style connector. So we may need to do some "rigging" of some kind to get it connected.

He sggested going to buy some anti freeze dye that will show up under a black light. Now I just have to find it

 

[Karnk]

Thanks for all the help guys. I was able to track down mechanic friend at his shop, never thought he would be there a week after having multiple heart attacks But he was

He has a tester, apparently it has a bladder style connector. So we may need to do some "rigging" of some kind to get it connected.

He sggested going to buy some anti freeze dye that will show up under a black light. Now I just have to find it

Looks like I might be having the same issue. Could you please update this thread with anything you find out?

 

[mickyd32]

Have not had a chance to dig into It lately
Soon as I do I will post