Dunlop or Hitachi compressors

[coopers1969]

Hello All
i did the full service on the original Hitachi compressor in my 2011 D4 hoping it would fix the issue with the air suspension. the issue i am getting it is taking a long time to raise the car and the compressor is running alot. the service kit didn't fix the issue so i am thinking of replacing the compressor. The AMK brands without delivery is over $1400.00 dollars where as a Hitachi branded compressor is just over 550 dollars is the AMK worth nearly 3 times the amount over the Hitachi brand. i do know the AMK is better but 3 time better it seams alot of money. but the old adage a poor man pays twice. Do i bight the bullet and pay the 1400 plus dollars for the AMk or will the Hitarchi one do the job for the next 8 years like the last one has. any advise from guys who have either brands replaced would be helpful.
cheers Adam

[Ean Austral]

When you done the compressor rebuild did you replace the plastic cap that the 2 airlines come out of on the top. From what i could see with mine and from reading many other threads , its the cap that is the main culprit most of the time as it develops hair line cracks between the 2 airline fittings. Some people have had success covering the cap in an epoxy glue like 5min araldite but i wasnt as lucky so needed to get a new cap after having done the initial rebuild.

I bought a hitachi off another member as it was a straight bolt in and the original lasted 9 years , and was still operating except the leaking cap caused the same issue you have.

Have you tried spraying soapy water on the compressor and fitting when its running to see whare the air is leaking from ? this would be my first option as you possibly could have a leak elsewhere , altho it sounds unlikely.

Cheers Ean

[coopers1969]

hey Ean i too read that but i didn't replace it as i had already purchased the the service kit without the cap. i was going to jump under the car tonight and spay soapy water and see if there are any bubbles.
so you still have the Hitachi compressor or did you go to a AMK model.

[loanrangie]

From what i have read the AMK doesnt seem to last as long as the hitachi,i'm still on the original at 11+ years and 175k so its doing well.
Unless the motor is burnt out you should be able to rebuild it to bring it back close to new, do you have the error codes for the current fault ?

[Ean Austral]

I stayed with the hitachi as 1 was selling at the time on the forum and i was about to do a trip so i.purchased that incase my new cap didnt arrive in time - which it didnt. I replaced the cap when i returned and fitted the old compressor which hasnt leaked since.

I know the AMK unit is meant to be the bee knees but i could justify the extra cost on a 9 yr old car that the original lasted 9 yrs and as it turns out is still going after a rebuild. Also check where the hoses go into the fittings , i ended up having to cut 1 of my hoses so just got some connectors and hose from enzed for less than $10.

Cheers Ean

[coopers1969]

From what i have read the AMK doesnt seem to last as long as the hitachi,i'm still on the original at 11+ years and 175k so its doing well.
Unless the motor is burnt out you should be able to rebuild it to bring it back close to new, do you have the error codes for the current fault ?
i can get the code and good to her about the longevity of the Hitachi compressors as i mentioned the first one has been OK for the last 8 years.

[PerthDisco]

So, can you still buy the Hitachi genuine original or is it Dunlop brand after market now?

[coopers1969]

I stayed with the hitachi as 1 was selling at the time on the forum and i was about to do a trip so i.purchased that incase my new cap didnt arrive in time - which it didnt. I replaced the cap when i returned and fitted the old compressor which hasnt leaked since.

I know the AMK unit is meant to be the bee knees but i could justify the extra cost on a 9 yr old car that the original lasted 9 yrs and as it turns out is still going after a rebuild. Also check where the hoses go into the fittings , i ended up having to cut 1 of my hoses so just got some connectors and hose from enzed for less than $10.

Cheers Ean
Ean
i will spray all around the hoses and compressor to see if there are any leaks and if there is try to fix them if that doesn't work i can get a Hitachi compressor from LR center in the UK. thanks for the ideas to problem solve this my indy wanted to charge me $2500 for a AMK compressor change over.
cheers Adam

[coopers1969]

I stayed with the hitachi as 1 was selling at the time on the forum and i was about to do a trip so i.purchased that incase my new cap didnt arrive in time - which it didnt. I replaced the cap when i returned and fitted the old compressor which hasnt leaked since.

I know the AMK unit is meant to be the bee knees but i could justify the extra cost on a 9 yr old car that the original lasted 9 yrs and as it turns out is still going after a rebuild. Also check where the hoses go into the fittings , i ended up having to cut 1 of my hoses so just got some connectors and hose from enzed for less than $10.

Cheers Ean


So, can you still buy the Hitachi genuine original or is it Dunlop brand after market now?
i believe it is Hitachi branded see link to the item you may be able to tell me if this a actual Hitachi it looks the same
.
LR025111 - Only PS300 plus VAT - Range Rover L322 Air Compressor for Suspension | LR Parts (https://www.lrparts.net/lr045444-oem-air-suspension-compressor-for-range-rover-sport-2009-2013-and-discovery-4.html)

[101RRS]

You will not get a genuine Hitachi compressor for $550 - they are knock offs and usually termed "Hitachi Type".

This is typical pricing of the knock-offs and the genuine item LR023964 | Air Suspension Compressor - Ds3 RRS - Land Rover Part LR023964 (https://www.lrdirect.com/LR023964-Compressor-Assy/)
https://www.amazon.com/Hitachi-Rover-LR023964-Suspension-Compressor/dp/B014LCNIA6


You can buy an "AMK Type" compressor (a knock-off) for not much more.


The Hitachi is fully rebuildable - what did you replace.

You need to do the dessicant, the filters etc which I assume you have done.

As Ean said you need to replace the cap TOOGOO for Land Rover Discovery 3 4 Range Rover Sport Air Compressor Dryer End Cap Hitachi: Amazon.com.au: Automotive (https://www.amazon.com.au/TOOGOO-Rover-Discovery-Compressor-Hitachi/dp/B07K9K66QL)

You need to replace the piston ring and guide.

You need to replace the exhaust valve as this causes internal air leaks out past the exhaust valve and no amount of squirting with soapy water will detect this.

[coopers1969]

Thanks 101RRS I have ordered the end cap and the exhaust valve I did the piston ring and the desiccant there is some leaking around the end cap out of the blue valve not heaps but still leaking. I am still getting the air pressure to low fault so hopefully changing the cap and the exhaust valve finally fixes it all cause if it doesn’t there is nothing else I can replace.

[crawal]

I rebuilt my Hitachi unit with this kit about 5 years ago using this kit

For Land Rover Discovery 3 4 Range Rover Sport Hitachi Air Compressor Repair 701851614575 | eBay (https://www.ebay.com.au/itm/Land-Rover-Discovery-3-4-Range-Rover-Sport-Hitachi-Air-Compressor-Repair-/221613451815?hash=item339930ea27)

Hardest part is doing the top bolt that holds the unit in but they tell me you slot the holder saves your sanity

[coopers1969]

That top bolt is tricky but not impossible and I can get it in and out within 30 min I have skills at working in tight places I own a 1969 mini. Nothing is as hard as working on one of those cars[emoji23]

[101RRS]

That top bolt is tricky but not impossible and I can get it in and out within 30 min I have skills at working in tight places I own a 1969 mini. Nothing is as hard as working on one of those cars[emoji23]

Take less than 5 minutes to get the top bolt out - just need a 10mm 1/4" drive with a 6" extension - goes straight on no issues as you are not in a tight spot but in clear air with the extension.

[coopers1969]

Well I have changed everything I can on the compressor and we’ll it isn’t completely fixed but it is better and should enable me to get anther couple of years before I have to replace it. If I come into any money I will replace sooner with another hitachi.

[loanrangie]

Well I have changed everything I can on the compressor and we’ll it isn’t completely fixed but it is better and should enable me to get anther couple of years before I have to replace it. If I come into any money I will replace sooner with another hitachi.If the dessicant had turned to powder it will have worked its way to the valve blocks , give it a week and you may want to clean them out.