Power Steering Pump- 3rd Replacement in less than 2 years

I appreciate you taking the time to share this info. I’ll definitely get on this.

Kicking myself when the problem originally presented itself it was within warranty, now it’s 5k miles out.

We’ll see. I’ll post an update when I know more

 

This is interesting, so I thought I'd make an account and comment. Howdy.

Q1 - do you know precisely where the leak is on the pump (eg at the pulley shaft, high pressure hose connection, reservoir hose connection, on the housing somewhere...esp at the pressure valve bolt)?

Q2 - you seem very confident it is the pump and not somewhere else it is leaking and I believe you, esp since servicing it 2x did stop the leak for many months each time. But, to cover that base, how do you know it's the pump leaking (and not perhaps say a breach in a hose/metal line immediately next to the pump?

Q3 - unlikely, but need to check it off...did you or anyone ever put anything into the PS system fluid ever (a fluid other than dexron ii or iii, perhaps something you thought was equivalent, an aftermarket additive, etc)

Thoughts:. (I got a real strong guess as to the issue, but I'll get to that in sec) Since you had a huge premature failure the first time, and it keeps happening, I agree this is unlikely 3 bad pumps. The fault, therefore, was likely there from the beginning and hasn't left. And, as stated before, pump is fixed temporarily everytime it is "replaced". I checked Google and Toyota Technical Service Bulletins for your model, and this appears not to be a pattern issue. And checked service repair manual and there is no special design technology about your ps system; it's a standard rack and pinion with a typical pump.

So, what are all the causes a ps pump (ie a ps seal, since all openings in the assembly have a seal) could leak? 1 - seal or mating service is faulty, 2 - fluid is incorrect type chemically or viscosity, 3 - fluid is contaminated 4 - pressure beyond the design spec is building up 5 - excessive mechanical stress on a seal

Here are the possible root causes I could fathom, from what I think is least likely to most:
1 - Someone added the wrong type of fluid or incompatible additive - unlikely. It's a new truck, no one would have a reason to screw with it and dexron ii/iii are ubiquitous
2 - Not PS, some other fluid instead and leaking somewhere else - It's a logical thought regarding the timing chain cover. However, I think the logic doesn't completely fit because... I - OP is confident the pump was leaking and the pump is in plain enough view to inspect. II - ATF (eg dexron iii) is dyed red for this very reason, so it's easy to identify, and with such a new truck, especially recently serviced, the fluid should not have changed color, unlikely. III - each time the pump was serviced, the leak stopped. If it was the valve cover, the leak would never have resolved. Also, the servicing meant another set of eyes besides the OP inspected it and agreed it was PS fluid, not something else.
3 - fluid is contaminated - given the arguments above, that already makes contamination very unlikely and would also be a short timeframe making it even more unlikely. Also, if the contamination were coming from parts breaking internally, you'd probably be experiencing significant other steering symptoms... there's not much in that system and it's all critical to functioning...rack and pinion gears, piston and seals, rotary valve, lines.
4 - using inferior non-oem part - has some logic, but doesn't explain the initial premature failure
5 - excessively strong drive belt tensioner - idea being it pulls too hard on the pulley shaft seal. not likely. Ive never heard of this, the mechanics of a tensioner would require a ridiculously strong spring acting over a long period; other pulleys would probably present symptoms if this were happening; the alternator is nearer the tensioner than the pump.
6 - (my second best guess) the shop has not actually been replacing the pump and lying and they have actually been pulling it open and adding an inferior gasket product or been adding it incorrectly - a shop would have a motiv for this because it would be quick, effective, and they could pocket the money charged to the OP for the part. If so, what would be happening is the original build of the pump is out of spec, which caused the original failure, and then when the shop tries to patch it each time, the repair keeps failing. This theory would quickly be debunked by looking at the pump after the repair and see if it's new. Also, I think the vast majority of shops are honest. Plus, risking your reputation on a measly PS pump replacement would be incredibly short sighted regarding the business and both the techs and management would have to be in on it.
7 - (here's what I think your problem is) your PS pump fluid reservoir cap (yeah the stupid little cap on the tank you put the fluid in) is faulty and the vent in the cap is stuck closed. - why do I think that... I -The way the pump system works is that it's always pumping and creating pressure when the engine is turning. When the pump reaches a max pressure, a pressure valve in the pump opens and sends fluid back into the reservoir, which adds pressure to the hydraulic circuit overall. Also, as the steering operates, the temp increases which expands the fluid which again adds pressure to the circuit. This is why a vent is built into that cap. If that pressure is not vented, then it exceeds the design spec which pushes excessively on the seals and they can leak. II - Everytime you got it serviced, being good technicians, they likely topped off the fluid, and maybe even you added a little extra for insurance...that would exacerbate the problem causing more pressure and the relatively quick failure the second and third time around. III - explains why you had the initial premature failure before the shop. Also, the vent probably worked for a number of years, then got stuck, which is why you got an initial 60k miles IV - Explains why the shop service works for awhile each time before it fails - you have to operate the vehicle for a good amount of time before the seals finally give out V - explains why the problem persists, why the shop is missing it, and why they can't explain it. Not thinking to check the vent cap is something a ton of people and mechanics would do, especially when putting a new pump on passes the test drive and is good for months after. I don't even think it's in the diagnostic tree in the Toyota official service manual. (Making me remember trying to figure out for months why my coolant kept disappearing slowly...vent valve in rad cap broke and stuck open) IV - although neither Google not the TSBs indicated this as a pattern for your particular vehicle, this is an issue a number of others have had on various vehicles. I did read a post from a guy with a Jeep who had this issue, so perhaps off road vehicles are likely victims just because these drivers go in dirty dusty places and the fine dust can float up into the vent and slowly block it.

What you can do: options - 1. don't touch anything, go to the shop, tell them your theory, if they think it's a good idea, they can test the cap, they'll pay for the new one, and it will be a teaching moment for the shop to update their procedures and maybe save them and other customers headache and money. (I'm not a mechanic, but I certainly wouldn't have thought to check the cap and would replace the pump just like they and you did) 2. Drive the truck for awhile to heat it up, pull the cap off, if you get an unusual pop sound, which might be hard to judge without experience, then the theory is supported 3. take the cap off, inspect it, try to clean and free up the vent valve, do the pop test above and see if fixed 4. Buy a new cap 5. Poke the smallest hole possible in the cap. Dexron can be exposed to air indefinitely I'm pretty sure and there's an infinitesimal chance of contamination or splash issues. 6. If you want the most assurance possible that the problem won't happen again and you are in the top 20% income bracket, go to dealer, tell them your theory, have them diagnose and replace the pump ($380 for oem part, about $150+/hr labor) and the cap and ... know we're grateful to you for distributing the economic wealth, get on a bi-weekly schedule with therapist and discuss your need to fruitlessly control all outcomes in your life and fear/disdain to adapt with the unpredictable challenges life presents. Joking.

Some resources if you'd like them:
Link to your service manual - https://cardiagn.com/2016-tacoma-power-steering/

Grest video on how steering system works - https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.youtube.com/watch?v=Jfgu0vgumK8&ved=2ahUKEwi5n7v6tOD0AhXVK80KHfVRDDsQz40FegQIFhA7&usg=AOvVaw2EOMv4W4jKYHugf41oyURz

Literally the textbook chapter on steering system -
https://www.dentonisd.org/site/handlers/filedownload.ashx?moduleinstanceid=101340&dataid=120402&FileName=Chapter 8.pdfceid=101340&dataid=120402&FileName=Chapter%208.pdf&ved=2ahUKEwio05SC3eD0AhVEGDQIHYIsDNsQFnoFCKMCEAE&usg=AOvVaw0m070t1vx0VPVMqvQm731m

 

agree, i have replaced one PS pump in over 40 years of driving and over 33 cars/trucks owned..

 

I appreciate you taking the time to reply. I’ll bring this up the shop, especially the vent cap. If I don’t feel like they’re going to get to the bottom of this I’ll take it to Toyota.

 

This seems to be the consensus. Even when they originally suggested replacement at 55k I thought it was off.

 

Part 1 update for anyone interested: Spoke to the shop owner, he said both pumps have been OEM. He said because the part is covered under warranty, when he sends the defective part back to the manufacturer, they confirm it’s a faulty pump otherwise the shop is on the line for the cost. The part manufacturer CONFIRMED it was a leak.

I bring it in next week to get a new one put in again. I told the shop guy to check the timing chain cover and reservoir cap etc and really get to the bottom of this. I feel like he heard me.

He said he has no idea why I keep getting lemon parts. Parts aren’t actually made by the car brand of course, so his best guess was maybe quality control concerns during part shortages and covid.


anyway I’ll update once they inspect and replace again next week

thanks for anyone who was interested in this. I know it frustrated me a lot so if this thread can help anyone else I’m glad it’s been of help

 

Im still banking on it being a timing cover leak.

 

Update and More Info:


Just got home from my appointment to replace the power steering pump to its 4th one in its 65k lifespan.

After I implored them to check the timing cover, they discovered a leak in the TIMING CHAIN TENSIONER ACCESS PANEL. They resealed this, and asked me to come back in 1,000 miles. I hope the writing isn't on the wall for a leak in the cover itself.... that's worst case scenario.

They did NOT replace my power steering pump again, as they now seem to think neither replacements were necessary. (though the original one at 55k miles was... they say).

Some other info:
-Confirmed they did replace fluid with Toyota fluid
-Even though they told me they used OEM parts, they clarified today they used OES.

Fingers crossed this fixes the leak. I definitely worry it's just kicking the can to a bigger issue but they seemed confident this would fix the issue. Not that I have much confidence in their diagnostic ability.

Thanks to contributors for your suggestions. You guys confirmed to me that the timing cover was probably the issue. I had my suspicions but lacked the confidence (and knowledge) to really insist they double check. You guys helped change that.

 

$20 its the timing cover itself.

 

Pretty safe to say the pump was likely never leaking. Hopefully that fixes it for you. If not the timing cover is a pretty major job.

The real shitty part here is had they diagnosed this correctly the first time you may have still been in powertrain warranty? A good chance Toyota would be fixing this on their dime and saving you from a hefty repair bill.

 

Exactly my thought. I think them saying one pump actually was leaking is just to cover themselves. If they’d checked the timing cover when I first asked it’d be within warranty.

 

It's always the timing cover lol.

 

Does anyone ever have luck getting Toyota to do work 5k outside of warranty if I explain the situation? Or am I screwed

 

Well.....you can try.

Suggest to remain calm when detailing the events and making the request. The Service Manager can exercise some discretion. But If you go all ballistic Karen....you will guarantee yourself no relief. Have your repair records on hand when you calmly speak with the Service Manager.

The worst they would do is say "No."

 

don’t worry my OS didn’t come with Karen mode

 

Replacing my left side CV shaft and upgrade to the ECGS bushing. When I dropped the skid I see oil on the right side and looks like the power steering pump. I read this post and now looks to be the timing cover. The power steering fluid is low so I'm going to clean up all the mess and see where it's coming from.

 

I haven't looked that close at my Tacoma, but how does a timing cover leak power steering fluid?

 

The leak looks like its coming from the PSP but this post is saying it could be the timing cover. I'm thinking it's the timing cover also after cleaning it up and looking closer at it.

 

I saw an oil drip from my 19 on my PS pump. I may have the same issue I will look a little further to see where it’s coming from
I thought this problem was only 16 ‘s and 17 ‘s, 27 k miles

 

FINAL UPDATE***
Checked 1,000 miles after applying sealant to tensioner access panel. Still leaking and very wet.

decided to take it to Toyota directly. They applied dye. Came back 2 weeks later. Confirmed my fears that timing cover is leaking.

timing cover gasket reseal quoted $4178.
Out of warranty because of original misdiagnosis. Will ask Christian brothers to pay and also keep my eye out for flying pigs.


Hope this thread has been informational for anyone else.

TL;DR: 2016 Tacoma timing cover leak. Leaking for 2 years now. Misdiagnosed as faulted power steering pump. Now out of warranty. Now at 67100 miles (roughly)