I cheat. If you use Diesel fuel to prime the HLA like they show in the 3000GT FSM you don't have to bleed them down because they will on their own once any pressure is applied.

Does the FSM say that? I just don't trust not having spongy HLA's to start out. Sure they pump up, but they don't butt valve heads, which I have had happen, ONCE.
Thanks for the comments, "cheater"
Marty

It's more what it doesn't say. Note there is nothing about bleeding them after, just getting all the air out.

From the 91 3000GT FSM Volume 1 (We use the same HLA's as the 6G72 DOHC)

Nice addition to the thread Steve!
Thanks!

Well Steve, I used the 3000GT method and I will say, flushing them in diesel fuel (I happen to have some on hand for a brush pile fire) works GREAT. It lubes and cleans. I still "bled" the liquid out but boy did it do a good job on old parts that you would think aren't good anymore.
I appreciate the additional info you provided!
Marty

1990TSIAWDTALON said:

Does the FSM say that? I just don't trust not having spongy HLA's to start out. Sure they pump up, but they don't butt valve heads, which I have had happen, ONCE.
Thanks for the comments, "cheater"
Marty

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I concur. Spongy HLA may rattle for a minute or two but that's it. Much rather hear that than valves hitting pistons.

I always install the lifters pre bled submerged in a cup of oil, and pumped hard prior to install. I’ve never had issues with lifter noise

To be technical you didn’t bleed the lifters in the video, you drained them of the oil and now you have to wait for oil flow into the head to fill them which will cause lifter rattle on the initial start.

Bleeding them to me means you are removing air from the lifters to fill them with purely fluid, just like bleeding brakes. In the video you are draining the lifters

To each their own. Most folks understand the concept, which is all the video was for. Those were old and dirty lifters as an example for a family member to see so he understood HOW to release the pressure from the HLA's. We talk on the phone, not here, so he gets the rest of the explanation and doesn't end up with more bent valves.
Do whatever makes you feel good and prevents engine failure. I always leave mine spongy. They pressurize right up when the engine starts cranking and making oil pressure.
For those "AI" guys, I added a picture of what it will tell you if you ask about "bleeding a lifter" on an engine. Trapped air will compress, trapped liquid will not.
Marty

1990TSIAWDTALON said:

To each their own. Most folks understand the concept, which is all the video was for. Those were old and dirty lifters as an example for a family member to see so he understood HOW to release the pressure from the HLA's. We talk on the phone, not here, so he gets the rest of the explanation and doesn't end up with more bent valves.
Do whatever makes you feel good and prevents engine failure. I always leave mine spongy. They pressurize right up when the engine starts cranking and making oil pressure.
For those "AI" guys, I added a picture of what it will tell you if you ask about "bleeding a lifter" on an engine. Trapped air will compress, trapped liquid will not.
Marty

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I'm going to agree with Marty. I've seen a valve hang open first hand from lifter that were not bled down. Oil, not air. I was taught this from a mitsu mechanic. I watched him start up fresh set and as you stated it made some noise upon first startup. He revved it for a little bit and it all settled down as it should. Every motor I've built and every lifter I've installed from a top end rebuild etc or just maintenance did the same thing. It isn't a big deal. To me a hung open valve is a big deal.

+1, I always install them spongy on every motor I've done, they quiet up in a couple minutes and never had any value train issues.

pauleyman said:

I'm going to agree with Marty. I've seen a valve hang open first hand from lifter that were not bled down. Oil, not air. I was taught this from a mitsu mechanic. I watched him start up fresh set and as you stated it made some noise upon first startup. He revved it for a little bit and it all settled down as it should. Every motor I've built and every lifter I've installed from a top end rebuild etc or just maintenance did the same thing. It isn't a big deal. To me a hung open valve is a big deal.

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I’ve seen multiple occasions of the lifters never filling and cars taking up to 50 miles to properly fill the lifters

I’ve seen multiple issues of the rocker arms coming off of the lifters because there is no tension on them when installed. The car starts and the rocker pops off the valve and due to the unfilled lifter, the rocker falls out of position

The lifters provide the tension for the rocker arms to ride the camshaft, there is no reason or explanation for a hanging valve due to the lifters being properly filled with clean oil. The camshaft is what puts the tension on the rockers and then the valves. Once the valves are filled with oil they do not release pressure and when removed they are always hard and prefilled

My gripe with this method is it should be called draining the lifters and not “bleeding the lifters”.

I’m not trying to change opinions on the topic, however this “dry lifter” method advice for a novice is not something I would recommend

I usually build 2 a year and have for many years. I've never had the issues you have seen multiple times. Even if I had, a rocker is a easy fix, a bent valve is not an easy fix and I DO recommend this if you are rebuilding one.
Everyone has there way but I don't sway on this and technically they are called Head Lash Adjusters or HLA's not lifters, as they don't lift anything.