Cam seals, Timing Belt Kit. If it isn't broke theory?

Talked to a local mechanic today who will be doing my timing belt and water pump. I purchased the highly regarded complete 15 piece kit from Aircabinman on Ebay and ordered the non reusable crank shaft pulley bolt from the dealer. In talking with the mechanic, I mentioned I had ordered the kit with new tensioners, pulleys, cam seals, etc. He said that he really doesn't advise changing the seals unless he actually finds one leaking. I understand his logic, but seals certainly age and or harden etc. and whose to say I wont develop a leak later on and have to pay more labor to get them pulled. He stated that unless the vehicle is sitting for long periods of time, the seals are being lubed and if they're not leaking he doesn't like to pull them. Essentially if it isn't broke, don't fix it. I can't imagine this is an issue of just not wanting to replace them considering how far into the front of the motor you are at that point anyway. If I recall on a previous 3rd gen 4Runner I had, the dealer that did my timing belt and water pump advised against changing them as well. What say you TW? Is it really better to leave them alone provided they are sealed and not leaking? Is there a high chance of a leak when installing new seals or something?

 

Seals leak due to age, meaning they get hard and brittle.

I don't change them on every timing belt job, but often once over 15 years old they are leaking. I'd rather have piece of mind and not have oil leaking on my timing belt.

My first shop in 2005-07 used to do cam seals on ALL t-belt jobs. It was overkill, but I got really good at the seals. The transverse 3.0 was a bastard.

 

So you would recommend me just telling him that I want them changed? I certainly mentioned the age and that's when he mentioned them getting lubricated by driving your vehicle and that this prevented this. I mean I really don't see the uneasiness on his part unless he just feels like if he replaces them and somehow there is a leak, then he will have to deal with it again as opposed to leaving the current non leaking ones alone.

 

I did exactly this. I have the seals from the same kit you got sitting on a shelf. Mine weren't leaking, and yeah, you can end up causing more trouble if you end up putting them in crooked or pinch it or something.

If the seals are still sealing, I'd leave them.

With things like the water pump, yeah, you gotta take that OFF anyway, to get to the timing belt, so year replace that. Or if you have to remove your manual transmission, definitely do the clutch, but the seals are just a little easier to get to when you're doing the timing belt and water pump.

 

You don't want to piss him off, but I would rather have it done now.

If some one asks a barber if they need a hair cut. They need a hair cut.

You tell me you need cam seals. I'm doing your cam seals.

 

We see varying opinions here because 1st gen range from 1995-2004 (9 years). It depends on the age and mileage. I recently changed all seals on a 1998 model engine with 70,000 miles. It had low mileage, but it was 21 years old. I plan to keep the truck for 10+ years or until it becomes impractical to keep based on parts availability. I've seen too many rubber components start to fail after 20+ years to just ignore it. You have a 1999 model. How long do you plan to keep it?

 

Well the truck has 196,000 on it and has always been taken care of. I am the second owner and I would love to get another 50K out of the truck before selling and getting a newer Taco. I just feel like the previous timing belt/water pump jobs that have been done have most likely not included all the little things like tensioners, pulley, seals, etc. and I don't see why someone wouldn't want to install them when they are that far into the front end. I feel like the truck deserves this much at this mileage. Anal perhaps and I don't want to come off as someone who knows everything yet doesn't actually perform the work, but I do believe preventive maintenance is key and this truck has served me well.

 

You have to remove cam gear(s) and the TB backing plate to get the seals removed. It's only like 6 bolts and takes a few extra minutes to do them. He already has the seals in hand. I don't understand why he wouldn't.

 

I would change them because when they do start to leak you'll have to take most of that off to replace it. It might not leak for a long time or maybe a little while down the road from you doing this but for piece of mind and having to pay for the work to be done again, Not worth the hassle to me. My suggestion would be to use oem toyota seals

 

It's an interesting question for sure.

When I replaced my timing belt, I replaced these seals - but it didn't go smoothly, I wrecked two seals (photo below) on the driver side cam shaft before finally getting the third one to seat properly by heating the race and freezing the seal. I wrote it up in my post here:

Yes We're Crazy Shop Day: Replacing the Timing Belt (and more) in Two Trucks At the Same Time

Here's the "issue," just so you're aware of it...perhaps for a conversation with your mechanic. The "easy" way to replace the seals is to pull them out and then press new ones into the races, around the cam shafts, all from the front of the truck, and without taking the top of the engine off. Usually this works. However, I believe the FSM states that the correct way to do this is to take the top of the engine off (intake and valve covers - I forget exactly where the "seam" that runs through the crank shaft race is) and set the seals in place from the top and then re-fasten the rest of the engine around them.

Toyota says to do it that way because the tolerances with the seals are very tight.

Will you run into issues? I have no idea. I did, but ultimately ended up getting a seal seated correctly and I am glad that I replaced them. At the very least, I'd have an extra seal or two on hand (or know where to get them from a local dealer) before replacing them.

And of course, many people have no problem at all.

tear in the seal that happened during install​

 

I’ve changed hundreds of cam seals without removing the valve cover or bearing cap, never an issue. Use some oil/lube & an installer tool, works perfect every time

 

Since your mechanic will be doing this work, I doubt this comment will matter. A couple of tricks noted in @turbodb and @Mehullica posts that I used to make the job go smoothly are listed below.

1) Freeze the seals the night before the job. This allows the seals to contract before installation. I was able to press the frozen seals 75% of the way into position using just my fingers.

2) Checked and buffed to smooth off the aluminum contact seam that seemed like it could damage a new seal.

3) Applied a very thin film of lubricant to metal part that makes contact with the new seal so the seal could slide over it and into position without binding on the surface.

 

will the mechanic discount the seal job say within a year IF an oil leak occurs? If he is that confident then leve them in. The other thing that effects oil leaks is the PCV valve... that is an easy replace as long as the grommet isnt rock hard.

 

Your in there all really, replace all those items and know your good for another 100k.

Personally I CANT stand any oil leaks anywhere, but that’s me.

 

I don't replace seals if they aren't leaking. I do replace idlers about 250k just because but I feel like I'm mostly wasting money there.