Coolant Leak

Hello,

Vehicle: 2005 Regular Cab 4.7L Tundra 4x4
Approx. 180,000 miles

My Disclaimer:
This forum is super helpful. I'm a 1st Gen Tundra lover. I own 3 Tundras and found this one that will be my work truck. I normally like clean, one/two owner vehicles. This is a beater. I bought it cheap. The future for this truck is a work truck beater, and maybe a light snow plow. I am no mechanic, this is a fun project for me and it is a beater. My other vehicles I let a reputable Toyota expert work on. I want to learn how to work on vehicles. This isn't my daily driver and it can sit inside waiting for parts or waiting for me to figure it out.

I just purchased this truck, and before I dig into the other problems, I need to fix this leak. Unknown service, but it does appear the timing belt has been replaced but questionable on the quality of the work. I searched and here is what I think. It’s future will be a work truck. The maintenance of this truck is questionable and I will be doing the Timing belt, water pump, ball joints, all fluids, shocks and struts.

Where I'm at:
I pressurized my system. I know I have a coolant leak but I wanted to narrow it
down. When I pressurize the system, there is coolant steadily dripping from
multiple spots. The biggest spot is on the passenger side of the engine block. The
oil pan is wet around the rim. The video is it pressurized so it really looks.



Leak Check from Shifty
Red = what I think
Blue = problems, but not the major factor of the leak.
1. Leaks on radiator body – X The radiator itself has no leaks.
2. Leaks on overflow tank or its tubing – X no leaks
3. Leaks from primary hoses/connections - there are leaks from the transmission cooler. Main issue is replacement lines and zip ties. Not the major cause of leaks, but will be fixed.
4. Leaks from where the tranny lines pass thru bottom of radiator
5. Coolant bypass at back of engine block (look where firewall coolant hoses connect to the block) - this is what I originally thought but the leak seems to be coming from the front of the block.
6. Behind the thermostat housing and in the valley behind/under the intake
Reading some other threads suggests it could be the O-ring on the front of the coolant bypass tube. The thermostat housing looks damp.
https://www.tundras.com/threads/coolant-leak-bypass-pipe-o-ring.81275/page-2#:~:text=#-,39,-oneoftheunderdogs
7. At the coolant temp sensor (ECT sensor)
8. Leaks from the radiator cap - X I pressure tested the radiator cap and it does not leak
9. Leaks at any block freeze plugs - The freeze plugs look dry. No leaks from the installed block heater.
10. Oil Cooler Hose – there is a leak from the oil cooler hose that drips pretty steady. I will replace the hose and clamps. This isn't the main leak, but still a problem.



I think it's time for me to remove the intake and look at the coolant bypass tube. Any advice if this is the right direction before I tear things apart. Thanks!

 

Remove your intake manifold and replace the O-ring in the coolant bypass pipe......DO NOT put silicone grease on it when installing. if anything, coat the O-ring with soapy water.
For sure, teardown to the valley and see what is going on.

The O-ring is at the front end of long round pipe.



Also check hoses going in and out of throttle body. Definitely check thermostat housing area as well.....

 

Thanks! I have the parts and have started disassembling.

 

Here’s a picture of my leak in that similar region. Note the dried coolant. This leak was significant and the engine fan was blowing it all over. At first I thought something up top, but was all dry up there. My valley was bone dry with no crust, no buildup on any thermostat/outlet connections.

My culprit was a Gates timing belt kit done roughly 40K miles prior by the PO. Water pump gasket failure, either by installer or part quality? I will say the Gates kit water pump was metal and a pretty solid looking unit.

I guess my advice is, if you don’t know the history of the timing belt/water pump, and you’re getting leaks from the front of the block, it’s likely worth investing in an AISIN timing belt/WP kit and going from there.

 

Aisin kit is the preferred kit........

 

This kit, specifically. Aisin makes one other kit with part number ending "001" which has slightly less stuff in it, and the lower price could be enticing for some.

Don't buy it on scAmazon.

 

That is exactly the one to buy .....

$188 Aisin TKT-021 Engine Timing Belt Kit with Water Pump - Compatible with Select Lexus GS400, GS430, GX470, LS400, LS430, LX470, SC400, SC430 Toyota 4Runner, Land Cruiser, Sequoia, Tundra

Aisin TKT-021 all good stuff in it.....

 

Aisin kit is sitting in the shop ready for me to figure to install. I think it could very well be the water pump gasket or when they did the timing belt. I found the radiator is loose so I'm not very confident in the previous owner's attention to detail. I'll start cranking this out the next week and see what I can get fixed. Thanks for the replies

 

I'm halfway through the redoing the timing belt and water pump gasket. So far, it seems relatively straight forward with the forum tools and the excellent Youtube available. It looks like the previous owner installed Gates stuff. The belt looks good but I've pulled it apart so putting the Aisin kit in. The water pump did have dried coolant below it. I think that is one source of leak.

I am still going to pull the intakes and check the valley. I tried looking with my cheap Amazon boroscope to look for any coolant leaks but didn't navigate the curves well.

Again, this is my cheap work truck but I decided to get a new Denso radiator and thermostat. Also ordered the Crankshaft seal. Hope I have all the parts for the intake... UPS has been getting alot of my money! Funny enough my dealer wanted $52 for the thermostat shipped here in 5-8 days. I did second day air for thermostat, gasket and crank seal for $60. Wish I had a good Toyota dealer!

 

Timing belt complete. I found two sources of leaks. One at the water pump and one on the radiator. I did not pull the heads for the valley. I decided to wait and see if it's fixed. The initial run looks like it's fixed, but I will pressure test it again to be 100%. I learned a lot about working on my new-to-me Tundra, which was the goal. I spent $1200 on parts and $200 on new tools. For my other Tundra, I paid a shop and local rates for labor only; the total was $800. The job took me 15 hours to complete. I took my time and cleaned when I could. It’s winter in Alaska, but this new-to-me Tundra could use a good pressure wash before servicing. A couple of parts runs and waiting on parts to arrive slowed me down. Overall, not a difficult task, but keep the hardware organized. I cleaned all my hardware in an Ultrasonic cleaner. I am no mechanic, but I found the YouTube videos straightforward. I also referenced the Factory Service Manual during the process.

Thanks to this great forum! I'm putting this here for future reference for next time

Lessons Learned

1. The best YouTube videos for me were TRQ and Timmy the Toolman.
https://www.youtube.com/embed/__7KouGrRfg?si=hJCZuMoBfJzv5Qz_

https://www.youtube.com/embed/zRPhl1xcYYw?si=WKyyFvsxHD2e9DXP
2. Crankshaft seal - I should have ordered this when I ordered all the other Toyota items.This slowed progress. I brought the Lisle Shaft puller 58430 piece (they include two) and ended up using the puller from Private Brand tools ‎PBT70960. Having the crankshaft seal tool kit made it easy.


3. Timing belt - getting this on was simple, following the videos. What worked best for me was started on the crankshaft to the left cam, then slightly moving the right cam, which is the method TRQ shows https://youtu.be/__7KouGrRfg?si=ojzHwvhGY7GLKL-B




4. Be careful of the camshaft position sensor. Do not pinch in the water pump. See this post: https://www.tundras.com/threads/trouble-shooting-a-no-start-issue.162027/#post-3997493

5. Make sure the crankshaft position sensor wiring goes behind the fan bracket. Luckily I saw the post about this because it’s easy to miss. https://www.tundras.com/threads/timing-belt-master-thread-sticky.107240/page-4#post-4102147


6. Buy a no-spill coolant funnel. I survived, but it made more of a mess and made checking for leaks a little harder.

7. Buy a bunch of quality spring band hose clamps. I had some leaks from hose clamps that were cheap and undersized. I replaced all my Power steering and coolant lines with Arctic grade 3/8" hose since that's a common problem in Alaska (had this on my last FGT). The Arctic grade is bigger outside diameter than the Toyota hoses, so I needed to order spring clamps. Spring clamp tools or 90-degree needle nose pliers are helpful.



Parts Needed

$188 TKT021 AISIN TKT-021 Engine Timing Belt Kit with Water Pump - Compatible with Select Lexus GS400, GS430, GX470, LS400, LS430, LX470, SC400, SC430 Toyota 4Runner, Land Cruiser, Sequoia, Tundra

TKT021 Aisin Timing belt kit $286 NAPA

Gates K-60908 Micro V Serpentine Belt $30 Rock Auto

Toyota 90311-A0001 Crankshaft Seal $13

$22 Toyota 90916-03100 Thermostat

Toyota 90916-03100 Engine Coolant thermostat $25

$12 Toyota 16346-50010 Genuine Toyota Thermostat Gasket

Toyota 16346-50010 Thermostat Gasket $6

$117 Aisin FBT-002 Fan Pulley Bracket - Compatible with Select Lexus GX470, LS400, LX470 Toyota 4Runner, Land Cruiser, Sequoia, Tundra

Aisin FBT-002 Fan Pulley Bracket $120 NAPA

Toyota 16210-50102 Fan Cooling Clutch $120

$23 Toyota 00295-00103 Formed-in-Place Oil Pan Gasket - 3 oz. Tube

Toyota 00295-00103 Toyota FIPG Seal Pack $15

Toyota 16572-0F011 Radiator Coolant Hose upper $49

Toyota 32942-34010 Radiator Coolant Hose lower $41

Toyota 16401-20353 Radiator Cap $25

Denso 2210517 Radiator $312 NAPA

2 Gallons Toyota Long Life Coolant 00272-1LLAC-01 $40

2 Gallons Distilled Water

Hose Clamps - spring type variety $25

3/8” Hose to replace transmission cooler lines $60


Consumables

Blue Loctite 242

Shops Towels

Rags

Disposable Gloves

Throttle Body Cleaner

MAF Cleaner


Tools

- 90 degree needle nose pliers

- OEM Tools spring clamp tool 25246 and Gearwrench hose clamp tool 3976D – not necessary but helped and aren’t expensive

- 3/8 drive 10mm, 12mm, 14mm Sockets and wrenches

- Flex head wrenches - I like the Tekton Long flex head

- 3/8 Drive swivel impact socket

- 22mm Socket

- 24” - 1/2" drive breaker bar for crank pulley

- M18 Milwaukee 3/8” Impact driver – I wasn’t sure if this would break the crankshaft bolt loose but it worked.

- 12V 3/8” Milwaukee Extended Reach Ratchet – not necessary but very handy

- Prybar set

- Crankshaft pulley holder – bought the cheap $20 one on Amazon

- Torque wrench ½” that does crankshaft bolt 180 foot pounds

- Torque Wrench – I used either my ¼” CDI 10-50 pound torque wrench or a 3/8”

- Extensions – variety of extensions for 3/8” drive. For the AC compressor, I went through the wheel well using 18 inches of extensions.

- Plastic and regular razor blades

- Coolant bucket

- Liste 58430 Crankshaft seal tool $20

- Crankshaft and Camshaft tool kit PBT70960 $130

- Tap and Die Set – I cleaned up the threads and fixed some studs that had the wrong pitch nuts installed.

 

Damn! That post gives shifty a run for his money on the details Great job.

 

Great job...you come out ahead always by DIY'ing it.......Congrats on a successful repair.......perfect positioning of belt on the "T" marks and down on the crank at the mark and threaded hole and keyway mark as well......Always best to use the "T" mark so the camshafts will not unload on you.....

You dont have to pull heads to check the valley.......only the intake maifold.......fairly easy job.......and you will learn more about your engine.....

Here is the best video hands down by a Toyota mechanic on a 4.7L......he uses the "T" mark and loosens the idler pulley for a little slack to get the belt on.

Watch entire video but especially the 4:20 to 5:20 sec mark....you will see his tip....the music in his video is annoying....I turned it off..

Last edited: Aug 15, 2022

https://www.youtube.com/watch?v=Z46cM-Bw1rI&t=269s

 

For someone who is "no mechanic", you're doing a damn good job!

I'm shocked with how rust-free your truck looks. I would've assumed they salt the roads heavily up in Alaska, but they must not! My truck doesn't look that nice!

 

Thanks guys! Always like to wrap up a thread when I ask for help and try to share what I learn. This forum is a great resource.