Quick Compressor Replacement Question

ryanjl

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Yes, you will need to reprogram going from AMK to Hitachi.

Also, the mounting bracket is different, so make sure you get that too.
 

avslash

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I have a random question after replacing my compressor.

There are three ports on the compressor. The inlet port which runs up behind the drive's tail light. The outlet port, which runs to the center valve block. And lastly, the third port which comes off of what I presume to be the drier on the compressor and runs to somewhere up in the vehicle.

What is this third port coming off the drier for. Some kind of pressure equalization vent or something?
 

Tapps33

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I've pretty much done it all to my suspension. I had the Hitachi compressor originally installed, but it died in 2019, so I replaced it with the AMK at the time. I was told it would last longer and would run a lot cooler than the Hitachi, but I honestly can't confirm that for fact. At the end of the day, they both worked fine. In my Hitachi's defense, I had a bad air strut and valve block at the same time...and that pretty much killed it.

Just so you know, the air lines are slightly different between the different compressors. (AMK vs. Hitachi...I don't know much about the Arnott version.) When I installed my AMK, it came with a conversion kit as part of the assembly. I also came with upper and lower cowlings because they are also slightly different as well. When I swapped mine I just unbolted the entire compressor bracket, and I'm not gonna lie, there's one bolt in the back that I could only get to with an open ended wrench and 1/4 turn at a time.....it was painful....getting it back in was even tougher....I want to say I unbolted the compressor from the bracket and was able to pivot it out of the way to get the bolt threaded. Sorry, it's been a while since I've done it.

As for new vs. rebuilding, I have replaced my front valve block 3 times, and it has recently failed again. I'm trying the re-seal route this time because everywhere I looked they were not in stock. (FYI, I was just looking last week). Also, because a $20 repair sounds a HECK of a lot better than a $200 one. Honestly, I think the seal may work, but I'll let you know when I get it back in the truck tomorrow. I did notice one thing, and that's the fact that it appeared one of the halves of my valve block was slightly warped. I should have taken a picture yesterday. Normally, the leaks are internal, but in my case I believe the mating surfaces between the 2 halves of the unit aren't true.....I know, this is your shocked face. Although, I now find myself wondering it the standard, "it's an internal issues with these valve blocks" is actually true. If the re-seal doesn't work, I am going to try and drill some additional holes through the 2 halves to run 2 or 3 additional screws for extra flattening force. I'll let you all know how it goes. I figure if it's already broke, I can't make it any worse! LOL!

Typically I'd say replace the blocks and go with new, but I'm on my 4th front block, which I'm now trying to fix....so new or old, it sounds like there's an issue with the quality of the parts they're putting out.

Almost forgot, this seems to be a good site that sells a lot of the repair parts you might want:

 

Tapps33

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I have a random question after replacing my compressor.

There are three ports on the compressor. The inlet port which runs up behind the drive's tail light. The outlet port, which runs to the center valve block. And lastly, the third port which comes off of what I presume to be the drier on the compressor and runs to somewhere up in the vehicle.

What is this third port coming off the drier for. Some kind of pressure equalization vent or something?
It looks like one is the air inlet and the other is an air exhaust line.

Screen Shot 2022-03-25 at 10.03.22 AM.png
 

ryanjl

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I've pretty much done it all to my suspension. I had the Hitachi compressor originally installed, but it died in 2019, so I replaced it with the AMK at the time. I was told it would last longer and would run a lot cooler than the Hitachi, but I honestly can't confirm that for fact. At the end of the day, they both worked fine. In my Hitachi's defense, I had a bad air strut and valve block at the same time...and that pretty much killed it.

Just so you know, the air lines are slightly different between the different compressors. (AMK vs. Hitachi...I don't know much about the Arnott version.) When I installed my AMK, it came with a conversion kit as part of the assembly. I also came with upper and lower cowlings because they are also slightly different as well. When I swapped mine I just unbolted the entire compressor bracket, and I'm not gonna lie, there's one bolt in the back that I could only get to with an open ended wrench and 1/4 turn at a time.....it was painful....getting it back in was even tougher....I want to say I unbolted the compressor from the bracket and was able to pivot it out of the way to get the bolt threaded. Sorry, it's been a while since I've done it.

As for new vs. rebuilding, I have replaced my front valve block 3 times, and it has recently failed again. I'm trying the re-seal route this time because everywhere I looked they were not in stock. (FYI, I was just looking last week). Also, because a $20 repair sounds a HECK of a lot better than a $200 one. Honestly, I think the seal may work, but I'll let you know when I get it back in the truck tomorrow. I did notice one thing, and that's the fact that it appeared one of the halves of my valve block was slightly warped. I should have taken a picture yesterday. Normally, the leaks are internal, but in my case I believe the mating surfaces between the 2 halves of the unit aren't true.....I know, this is your shocked face. Although, I now find myself wondering it the standard, "it's an internal issues with these valve blocks" is actually true. If the re-seal doesn't work, I am going to try and drill some additional holes through the 2 halves to run 2 or 3 additional screws for extra flattening force. I'll let you all know how it goes. I figure if it's already broke, I can't make it any worse! LOL!

Typically I'd say replace the blocks and go with new, but I'm on my 4th front block, which I'm now trying to fix....so new or old, it sounds like there's an issue with the quality of the parts they're putting out.

Almost forgot, this seems to be a good site that sells a lot of the repair parts you might want:


What the heck are you doing to go through 4 front valve blocks?

What year is yours? Mileage? Are you using the OEM ones or the cheaper ones on Amazon?

I'm on my original front valve block at 112k miles in my 2012. I took it apart once to see if it needed cleaning. Just a few specs of dessicant that I blew out and put it all back together.
 

Tapps33

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I've got a 2010 LR4, 170K on the clock, and I have no idea why they keep failing. I think the first replacement was in 2016ish with about 100K on the clock when the fronts started kneeling overnight. Then, I went and did it again in 2018 because it was starting to go down over night again, but only later discovered it was both the valve block AND a leaking strut...that time it had killed the compressor as well...talk about chasing several issues at the same time! Totally had to drive around on the stops for a week or two while I waited for parts to come in...thankfully we didn't really have to do a lot of driving so it was ok. At that time, I replaced all the air struts as well as all the valve blocks, swapped from Hitachi to AMK compressor and swapped all the front air lines, just in case. (I was still chasing leaks at this point as well) My thinking was basically the same as @avslash, just go with new all the way around and all will be good for another 100K miles. However, the front block started leaking again about a 6-8 months ago. FYI, this is my wife's DD, and we don't take if off road aside from the random trip to the dump.

I believe I went with a cheapie valve block the first time, but then went "Genuine LR" the next couple of times. I know when I basically rebuilt everything, I went genuine parts for everything, (Yes, my wallet is still screaming!) The only exception is that I went with Arnott air struts....FYI, I LOVE the Arnott struts. They're a little stiffer than the OEM ones and I feel like the truck handles a little better. Don't get me wrong, it's not a new BMW X5M or RRS SVR, but for the gigantic LR4, it does a little better....it could also have been the old struts were leaking and worn out so by default the Arnott's felt better.

I do have an update on my repair, my resealed block is back on the truck and by all accounts is holding tight. I'm going to let it sit all weekend long and then see if its fallen at all, but so far, all seems to be good.

I should also point out, I don't remember seeing any desiccant dust when swapping my valve blocks out or servicing the system. I know this time, my valve block looked pristine when I re-sealed it. As I said before, I sprayed WD40 to loosen the air line fittings on the valve block as there's nothing worse than loosening the line a full turn only to have it re-tighten itself 15/16's of a turn. When I took the block apart, I noticed there was WD40 inside one of the valve bores. I can only assume this is because the large outer o-ring was my point of failure/leak.

I feel like the quality control for these parts is hit or miss. I also feel like there's a design flaw with these valve blocks. Oddly, it looks like they were originally designed to have more screws holding the block halves together, but some engineer decided they didn't need them. I could be wrong, but it wouldn't be the first time LR decided to save a buck by reducing the number of stainless screws they used!
 

Tapps33

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Well, it appears as though the re-seal didn't work. the front is back to falling down over night. :bawling:

Looks like it's time to order another valve block... or Maybe I have a leak somewhere else? I dunno...
 

ryanjl

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Could be the center valve block.

Have you pulled the EAS fuse/relay and let it sit overnight to see if just one corner drops?
 

txfromwi

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If anyone is interested.

IIDTool Menu

With the vehicle running...

Main Menu
ECU Flash
RLM-Suspension

At this point you can choose whether to change your software to Hitachi or AMK.
You can also take a look at what you already have installed.

Identify Actual Firmware

That way you can plan the parts in advance of opening it up.


I just checked the 2013 and it came from the factory with AMK.
 

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