Coolant Leak Troubleshooting Steps

[2001LC]

Some band-aid jobs. They really held well But new OEM replacement parts is best.

These shots while FIPG still wet withing 3 minutes of application in water bypass inlet O-ring port. I than scraped flush with time limit. Worked very well.

 

[2001LC]

So if we can get by with 1 vehicle for a while, are you saying I should 1. drain coolant, 2. disconnect all hoses and check for leaks, pitting, etc. on the front and rear water by-passes? (Or would that necessitate having replacement gaskets on hand)?, and then 3. order all parts I'll need?

I work from home and we have 2 vehicles, so not a deal breaker if I had to take some things apart then order parts from Dubai and wait a week for them to show up.

Or, set up tester at 15PSI, leave cardboard, wait for leaks to show, and then do the above?

I guess I'll follow the first above advice from @jerryb -- remove the underengine pan, put down clean cardboard, reconnect the tester at 15PSI, and wait. (Question: How long is long enough!) before doing anything else.

I mean, even if there was heavy pitting on the by-passes and front inlet, adding those, 4 gaskets, even the nuts (bolts not available at PartSouq)... it would bring the total to $533.90 $562.50. With my context of wanting this LC to run for a long time and not strand me on any adventure trips, that seems like a small price to pay (IF I had to replace the by-passes, inlet, etc, not just doing just because). I shudder to think what it would cost to have a dealer or shop do this... think the dealer charges something like $128/hr...

Only disconnect hoses you must. Which would be during a service like H.TEES, thermostat, time belt or hoses showing signs of leak.

Pressure test if helpful. But visual inspect is must for pinpointing of leak. Toyota coolant leaves a red or pink crusty, if present for sometime. After repair pressure and visual again, is just good practices and visual most used.

Band-aid or replacement, is a personal option. But replacing gasket(s) is must, whenever removed. Place old or new OEM clamps back in same orientation into impression of rubber hose, is key to no weepers.

 

[2001LC]

Also learn to top properly.

After reaching operating temp and reaching RPM of 2,500, with both heater turn up to HOT.
Let cool down overnight, with front of vehicle higher than rear. This put air pocket at top of radiator (high point).
Remove radiator cap in early morning, before rising OAT/sun heats up coolant/vehicle. Fill to neck of rad cap, so no air in radiator.
Bring level in reservoir up to above low line at OAT of -20F, to High line at OAT of 100F

If radiator took more coolant, repeat again next day. Keep repeating until radiator does not take more coolant, plus one more check to see full.

Never ever use tap water....... not as additive nor as flush.

 

[TheBestCow]

Look what I found... took under engine cover off and starting looking up. If you zoom the photo it looks like it is coming out from around the bolt?? What bolt is that?

Have the tester on and sitting at 15PSI... no drips coming out that I can see, have had it on for an hour so not obvious trickle or anything. After about 2 hours did drop about 1PSI to 14 but not sure if that's the tiniest of leaks or an imperfect loaned tool.

EDIT: Actually, now that I look at it, I'm wondering if part of the part on the metal (not the bolt) is from where I sprayed some Simple Green to try and clean off the top side and it dripped down to the bottom and left some residue? Either way it looks like maybe it's been leaking from there, then dripping down onto that bolt. I've Simple Green'ed the bolt and scrubbed with a toothbrush, then rinsed it with clean water from a spray bottle, will have to wait until it dries and then check again.

Either way, at bare minimum I think I'm in for all the hoses and clamps, plus thermostat and gasket. Get all of that knocked out and then know it's been taken care of. If the original hoses lasted 245k miles that should do me just fine. I'll drain the coolant this weekend, check for pitting, and then order parts. If I'm going that far is there anything else (besides the water intake, water by-passes and gaskets, trying to avoid that if possible).

 

[awesomeissquid]

Might want to order an extra thermostat gasket incase it gets messed up on install.

 

[TheBestCow]

Might want to order an extra thermostat gasket incase it gets messed up on install.

Yea, was going to triple check the list and probably order some extra clamps, too. Good call on the extra gasket considering it is $2.22. This thread talks about how the part diagram can be wrong for 2000s with the clamps listed, so trying to not get everything apart and be missing a clamp or two.

Guess I'll have to quadruple check the PartSouq part diagram again to make sure.

 

[TheBestCow]

Update.

Coolant drained. Got maybe 3.25 or 3.5 gallons out of the three ports. Nice, red, looks good. Don’t think a flush will be needed - looks like when they replaced the Heater Ts ~6000 miles ago they did a good job on the coolant.

Got the hoses disconnected from the radiator — radiator side looks good.

Got the hoses for water inlet, front water by-pass, and rear water by-pass disconnected. Water inlet, rear by-pass, and return line look good (although the hose on the return line must’ve been original because it took AGES to get it off. I ended up having to cut the hose to get it off to check for corrosion).

Ordering all new hoses, Ts, and clamps/clips. Will keep these Ts as emergency replacements in vehicle.

Now, the front by-pass looks like this. Light gunk and pitting. Cleaned it up with a scour pad and simple green. Results below. My guess is this isn’t heavy enough to justify going through the process to replace the front by-pass — but could do it at next timing belt/water pump (if I ever get enough miles on it to make it to the next interval!)

Thoughts?

Started looking like this:

Cleaned up to this:

 

[AlpineAccess]

I would clean that surface with alcohol and then apply some FIPG with a flat scraper like a credit card. The majority of the "seal" on the hose is being provided by the lip closest to the paper towel you have there; however, the clamp is ensuring that pressure that leaks past doesn't escape so you want it to seal tightly. FIPG would work well in this case to seal those small voids if it is allowed to dry before you put the hose on.

I have replaced pitted coolant piping like that before, and I have also worked on friend's who were less discerning than I was and we used FIPG. Both cases we found the parts sealed well and even after 10+ years no leaks from the FIPG components.

 

[TheBestCow]

I would clean that surface with alcohol and then apply some FIPG with a flat scraper like a credit card. The majority of the "seal" on the hose is being provided by the lip closest to the paper towel you have there; however, the clamp is ensuring that pressure that leaks past doesn't escape so you want it to seal tightly. FIPG would work well in this case to seal those small voids if it is allowed to dry before you put the hose on.

I have replaced pitted coolant piping like that before, and I have also worked on friend's who were less discerning than I was and we used FIPG. Both cases we found the parts sealed well and even after 10+ years no leaks from the FIPG components.

Denatured alcohol and which FIPG? I think I read there are different types — black, gray, for super long coolant, etc.

1990-2006 Toyota Oil Pan Sealer 00295-00103 | Toyota Parts - https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-oil-pan-sealer-0029500103?origin=pla&gclid=CjwKCAjwjuqDBhAGEiwAdX2cjxvTWe3Fh4r3eJgAvD6EIQVVx2u8sh0c9sSkZjY2VvQ5s5P6GsRrIBoCCr4QAvD_BwE

Looks like this is the right one?

And would I apply to the whole aluminum past the lip, or just to the holes and use the flat scraping method?

Now that I’ve successfully learned how to drain the coolant I’d lean toward FIPG and wait. If it gets worse I would replace and do whatever else is involved in the “while you’re in there...” section with the front water by-pass.

 

[2001LC]

Toyota 1282B FIPG is for coolant.

 

[TheBestCow]

Toyota 1282B FIPG is for coolant.

Thoughts on this AISIN as an alternative to the $70 tube of magic? Can be had on RockAuto for $12.47+shipping. Seems logical if AISIN is putting it in their timing belt kits and states it is good for water pumps, and I'm only using it as a secondary seal over a bit of pitting?

Or even Permatex 22071 for something like this for $5?

At one point you said a Toyota tech told you they could get away with 103 on vehicles that used Red, but not Pink.

Time to cure is not a problem. I can let it sit as long as I need to.

 

[2001LC]

I only use Toyota 1282B.

Aisin has one they recommend with their water pump (same as Toyota)? some have used! It may be the same as 1282B IDK.

Yes I was told 102/103 could be used on red. As stated now and back then: I only use 1282B.

"A Toyota shop once said to me, we can get-away-with 103 in system that use Toyota LL (red) but not in systems that use SLL (pink), IDK. I have found issue with leaks in some rigs that I suspect was due to wrong FIPG or contact with coolant to soon. But they could also could be from not cleaning surface properly before applying.

I just follow the FSM and use 1282B always, and don't worry about it."

For a temporary band-aid as long as you let cure before assembly the Aisin coolant rated would be a 2nd choice.

 

[TheBestCow]

Getting ready to apply the FIPG in next few days. Am I only looking to fill in the chunks/holes, or do I want a smooth coating all the way around?

 

[TheBestCow]

I would clean that surface with alcohol and then apply some FIPG with a flat scraper like a credit card. The majority of the "seal" on the hose is being provided by the lip closest to the paper towel you have there; however, the clamp is ensuring that pressure that leaks past doesn't escape so you want it to seal tightly. FIPG would work well in this case to seal those small voids if it is allowed to dry before you put the hose on.

I have replaced pitted coolant piping like that before, and I have also worked on friend's who were less discerning than I was and we used FIPG. Both cases we found the parts sealed well and even after 10+ years no leaks from the FIPG components.

I’ll admit it looks a lot more lumpy in the photos than it does to the naked eye... but is this the general idea?

Not putting hoses on until Saturday, so more than enough time to cure.

 

[awesomeissquid]

I think ideally you want to scrape off the FIPG so it is only filling the voids that are created from the pitting. See post #21 where @2001LC did just this.

 

[TheBestCow]

I think ideally you want to scrape off the FIPG so it is only filling the voids that are created from the pitting. See post #21 where @2001LC did just this.

Well... crap.

So scouring pad and denatured alcohol to clean it all off, then go back and apply new and let sit for a few minutes, then scrape so it only fills in the chunks and gaps?

Or are you saying I can scrape it tomorrow to just being filled in gaps? Not going to be able to get back to it tonight.

Learning a lot it seems!

Edit: got most of it off without denatured alcohol, which I am out of, so will clean it up tomorrow. Will see if I can find a way to just fill the gaps and scrape off the remainder after I get it cleaned up

 

[2001LC]

You can try lumpy. If it than leaks/weeps come back, remove hose, removed FIPG and start over.

But generally we scrape flush while wet, only filling in holes. This is done within first 3 minute. After that do not touch until cured, about 24 hours.

 

[TheBestCow]

You can try lumpy. If it than leaks/weeps come back, remove hose, removed FIPG and start over.

But generally we scrape flush while wet, only filling in holes. This is done within first 3 minute. After that do not touch until cured, about 24 hours.

Yea I went ahead and removed it last night and filled in just the holes and scraped, as best I could. Not perfect, but definitely not thick and lumpy. End result while it cures. Going to give it a full 24 hours and put the hoses on tomorrow.

 

[TheBestCow]

Checking all the ordered parts before my 7 year old and I start tackling this tomorrow.

Newbie question here... is the new thermostat supposed to look like this with the discoloration on top?

Any other pointers for removing all of the hoses, the oil cooler coolant hose, etc.? Any special lubing I’m supposed to do before connecting hoses? How high or low on a hose should the clamp be?

Rather ask a basic question and get it right than to not ask and get it wrong. I know I can try to mimic what is already there from a clamping standpoint, but just wanted to triple check.

 

[94SRUNNER]

Checking all the ordered parts before my 7 year old and I start tackling this tomorrow.

Newbie question here... is the new thermostat supposed to look like this with the discoloration on top?

View attachment 2661459


Any other pointers for removing all of the hoses, the oil cooler coolant hose, etc.? Any special lubing I’m supposed to do before connecting hoses? How high or low on a hose should the clamp be?

Rather ask a basic question and get it right than to not ask and get it wrong. I know I can try to mimic what is already there from a clamping standpoint, but just wanted to triple check.

Is that thermostat OEM and is that rust?