2005 - replacing engine coolant/water pump

Hi folks,

I've scoured the forums here in preparation for a DIY engine coolant/water pump replacement this weekend (inc. serpentine belt).

At 140,000 mi on my 2005, I started noticing a grinding, 'bad-bearing' noise ("crrr crrr") when the engine was cold, but it would soften or disappear after the engine became warm on the road. Now near 150,000 mi, the noise is louder and always present when the engine kicks on; it stops when coasting. The pulley has a very slight wobble when spinning. I placed my ear on end of a long metal rod which focused on the water pump to confirm it is bad. No evidence of leakage (pink coolant stains or formations) on the pump itself.

I'm referencing the below URLs for the maintenance:

Water pump replacement overview:

Excellent description - How to replace engine coolant pump and thermostat | PriusChat
Visual overview -

(the mechanic's working on a 2006 but it gives a feel of correct disassembly/re-assembly order. For bleeding the coolant, I've read running the CHRS pump via Toyota diagnostic software or manual relay is faster than running it in maintenance mode)​

Coolant change overview:

Part 1 drain/refill -

Part 2 bleeding air -

Description - Changing engine coolant | Page 3 | PriusChat​

Parts ordered online:

- ($34 inc. shipping) GMB water pump
- (2 ga. @ $53 inc. shipping) Toyota 50/50 Pre-diluted SLLC coolant
- ($15) Dayco PolyRib W Profile serpentine belt
​

Equipment (will need to pick up locally before weekend):

- 10 mm 3/8" socket wrench
- latex gloves
- basin to catch coolant
- allen wrench for radiator (size?)
- voltmeter (if running CHRS pump via relay terminals)
- tube to drain coolant from radiator back to funnel (size?)
- silicon to hold gasket in place
- anti-seize for bolts
- coolant funnel
- a second bleeder for the radiator​

'Borrowed' via Loan-A-Tool through AutoZone (thoughts?):

- AirLift made by UView (Matco AirLift)?
- inch-pound torque wrench
- water-pump pulley tool (necessary if screwdriver works just as well?)​

I think the bulk of prep is in order, but also think public oversight might save me (and potentially future readers ready to conquer their pump) a few minutes of labor/frustration or an inconvenient, mid-repair store-run. If anyone sees a 'duh, you need this' component missing from the above, let us know!

Thanks for reading,
David

 

Thanks all for your input - this is great!

As a fairly recent college grad, husband and now father, I default to the lower cost items, but if OEM is only dollars more in this case, it might be worth the spare change for a lower cost of total long-term car ownership/repairs.

Yes, the idler pulley has no wobble at all, even when giving it a good torque sideways. Good call on checking radiator days after - I shall.

True, however there's been no evidence of leaking underneath at parking spots.

Good to know, I've never seen one in action. I think I can get my hands on a compressor...

Interested in any further suggestions!

 

Success!

It took about 4.5 hours all-in-all, including a trip to the store for 4' of 3/16'' inner-diameter tubing for the radiator bleeder.

Draining coolant:
I began by loosening the front passenger-side tire lug nuts (not removing), then jacked up the passenger-side, securing it with a jack before removing the front passenger-side tire. The emergency brake was applied. The black front driver-side fender under-cover was removed to access the CHRS canister for draining the coolant. After removing the gray electric clip from the canister and placing newspaper on the ground with a basin, I loosened the yellow plug to drain around 6 qt. of coolant (also removed the radiator cap to expedite drainage). I didn't drain from the engine or radiator.

Prep work:
After setting aside the air filter intake, I felt the tension in the belt for future reference, and then loosened the tensioner pulley (pulley bolt with 14mm wrench and front-facing 'tightener' bolt with 12mm socket and a couple extensions) and removed the old belt. Then got under the car to remove the black passenger-side engine under-cover and passenger-side fender under-cover - this allowed convenient access to the water pump and particularly the pulley bolts. Using a 1/4'' mini-ratchet, I had clearance to loosen the pulley bolts (10mm) while placing a screwdriver through one of the pulley holes to prevent it from rotating. I couldn't have done the job without that mini ratchet, which was the MVP tool today.

Replacing pump and belt:
After removing the pulley, I removed the water pump by first removing 2 bolts and 1 nut from above (10mm) and 1 bolt and 1 nut from below (10mm) - 3 bolts and 2 nuts total. A little coolant spilled after removing it so place a basin under to catch it. The old pump has a bit of play in it and a 'crr' noise when turned. It certainly had evidence of weeping/leakage. The gasket is metallic. The new gasket is more of a paper/cardboard material. New pump inserted (bolts/nuts @ 8.1 ft-lbs) and pulley (bolts @ 11 ft-lbs). New belt installed and tensioner pulley tightened so that belt was as taut as before.

Adding new coolant:
The yellow CHRS plug was tightened with electric clip now re-connected. I loosened the radiator bleeder with a 6mm hex and placed tubing (1/4'' inside diameter) on the nipple but it was too big and didn't seal even with vise grips. Use 3/16'' inside diameter tubing (cost me a store run)! I poured in around 3 qt. coolant via a funnel over the radiator before the radiator stopped taking it in. At this point, I manually ran the CHRS pump with a multimeter, but it ran at a high pitch and 1.0A, so I think fluid hadn't made it to it yet. After some long wait times and forcing the funnel over the radiator intake for a seal & topping it off, the coolant levels just didn't appear to drop. I started the engine for a couple seconds where it started gulping it in with several bubbles. Now the CHRS pump amperage & pitch varied as it ran, suggesting it was pulling both fluid and air now. We ended up pouring almost 8 qt. in, until the CHRS pump ran steady at 2.8A and no bubbles coming through. We thought this was because my coolant level was too low initially, draining at 6qt.

Wrapping Up:
After replacing the black under-covers and the front tire, I lowered the car and started it up - it would barely accelerate with the engine running. After a few adjustments to the tensioner pulley, I realized the emergency brake was still in. X_x

All done. Thanks all for the help - I saved a few hundred today.

MVP tools:

- 1/4'' mini-ratchet (for pump pulley bolts)
​

Bad pump on engine by productofdesign posted Feb 20, 2016 at 4:43 PM

Bad pump & gasket - removed by productofdesign posted Feb 20, 2016 at 4:43 PM

MVP Tool: 1/4'' mini-ratchet by productofdesign posted Feb 20, 2016 at 4:43 PM

 

I ended up putting in the GMB water pump. No sealant was used per a number of people's comments that it was unnecessary.

On Sunday morning (one day after), I saw wet spots under the car by the water pump and the bleeder valve, which made me initially anxious. Thankfully however there has been no evidence of further leakage, so I think this was residual drainage from the maintenance's coolant spillage/bleeding. I'll post later if it turns out otherwise (fingers crossed)!

 

So I was hoping this story was wrapped, but recently there's been a small wet spot under the car after sitting overnight.

The overflow tank was around or below LOW, so I topped it off with the leftover coolant from the maintenance.

It wasn't leaking at all for the last couple weeks, but now (as the temperature is rising?) it is unfortunately.

I dropped by a mechanic today who said don't tighten the pump any further - perhaps I nicked the gasket putting it on.

I'm just trusting the new pump hasn't failed already - it sounds great when running.

Is this a common issue on DIY for coolant pump? I plan to visually inspect it on Saturday, but am ordering more coolant in case I have to wait for another pump (I commute 45mi one way for work).

Thanks,
David

 

Is adding sealant (silicon?) to the gasket after the fact a viable option? I'd likely drain/refill with the newly added coolant, ensuring the plastic ware is clean.

Disassembling the pump, adding sealant and closing it up should go much faster this time around.

 

Thanks guys - we are learning!

Yesterday I put the car under the knife again to replace the paper gasket with an OEM gasket ($9.30).

After draining the coolant and removing the engine undercover, it was clear the gasket seal was seeping and not the weeping holes which are indicative of pump failure (I think). While removing the pump, I noticed the most 'posterior' nut felt loose already, which was disenchanting. I scrapped off all the residual paper gasket on the pump and engine block before installing the OEM metallic one (no sealant). Pump bolts/nuts were tightened to 8 ft-lbs (96 in-lbs) as before.

Then I re-filled the coolant and ran the engine to test for seepage - unfortunately there was a tiny amount that came through, forming a 'drop' by most 'caudal' pump bolt (closest to ground). This is presumably the exact same phenomena that I was trying to fix! Removed the tensioner pulley and pump pulley, and further tightened the pump bolts to very tight (without torque wrench). Ran the engine again with the same results. It was getting late last night so I had to wrap up knowing it's still seeping. This morning I see fresh drops on the ground.

During the night I had the thought that perhaps the pump bolts/nuts have been tightened in the wrong order (top 3, then bottom 2). Perhaps if I loosened the top 3 then wrenched down on the bottom 2, then re-tightened the top 3 we'd be in good standing. Ideally, the pump would be fitted using the same star pattern we use for lug nuts on wheels, but I'd rather not drain/re-fill the coolant a third time.

The seepage isn't detrimental, but it'll probably take a gallon of coolant every two months at the previous rate (which is still cheaper than forking over $250 for mechanic to do the same steps, presumably). But I'm not sure what current rate it's leaking, whether better or worse than before.

Possible next steps:
1) loosen top pump bolt/nuts, tighten bottom then re-tighten top (to torque pump towards better seal at the bottom)
2) Is there a sealant to place at the base of the pump as a last-stand workaround?
3) Buy OEM pump and re-do the maintenance again

Thanks all for your thoughts!

The good news is I'm getting familiar under the hood with so much time lately - I might do some rust maintenance on the radiator bracket next go around which is getting thin-looking.

 

Thanks, if anything I left a few gasket bits on both the pump and housing. It was a very gentle scrape that probably left too much on. I had planned on the gasket falling off, not falling apart ..

At this point, the next maintenance will see to the following:
A. Clean residual gasket off of pump & housing with Scotchbrite
B. Apply silicone beads on both gasket sides
C. Tighten water pump using start-pattern (opposites)

If I didn't have the Lisle funnel, this would be an ambitious amount of work & time for this leak.

If you guys have any other tips, let me know. As they've said in construction:

"Think more, work less."

BTW: the picture below is right after removing it. I cleaned it up except for a few particulates.

 

To follow up on this, I did pick up the black FIPG gasket, however ...

Tthe leak issue resolved itself, probably from residual coolant crusting and sealing the pump. No problems since Mid March, but I'll be ready this winter if it arises once more.

Thanks all for resolution on this one!