Community Forums

IanSmith-UK · 07-23-2020, 12:08 PM

Quote:

Originally Posted by discovery39s

Replacing either HEUI is around 1.5-2.5 hours depending on coach design. It's not the replacement of but more accessibility to get to it. I'm blessed on my Discovery for the fact the 3126 is wide open due to the dual floor access points. ..................................

You really do not want to see any metal whatsoever.
Hope this helps

Here, here, George

HEUI access / restore on our C9 Country Coach Allure is around 3 hours each way, owing to need to access via bedroom floor to disconnect muffler, up in the air to remove muffler, allows access to remove air compressor - you can then access the HEUI - time consuming but not overly difficult

HEUI pump itself replacement not difficult (2 hours max) - BEWARE Caterpillar's use of steel unions into a machined aluminium casting on the diesel transfer pump

- over tighten at your peril

Note that Caterpillar undertook a number of significant improvements to the HEUI pump design / construction in circa 2007 - the minimal 'core' charge when replacing a pump suggests that they appear only interested in the casing ??

'Multiple Improvements have Been Made to the Hydraulic Electronic Unit Injector (HEUI) Pump Used In All C7 and C9 Engine Applications{1714}' Special Notice
(or pm me with private email and I will happily forward a pdf copy)

Safe travels all - from the UK

Ian S.
Exeter UK
CC 2005 Allure
CAT C9 #9DG02935

discovery39s · 07-25-2020, 08:09 AM

Hi Ian,
Yes, it's all about access. As you experienced with your coach months ago, it can be a real challenge depending on the coach builder. I had one three weeks ago that was NO FUN. I had to cut and bend wrenches to get fittings loose. It's a Houdini need with some.
Good to hear from you and hope your safe across the pond.
George

Don G · 01-21-2021, 07:59 PM

Quote:

Originally Posted by discovery39s

ANY additional filtering on any system will aid in the contamination potential. The pre-filter to the HEUI will avoid potential damage to the HEUI if the cooler plate is distorted and leaking unfiltered oil to the system Not only is the HEUI at risk but also every other bearing surface. However, if the root cause, requiring the pre-filter, is the cooler plate then why not fix that and allow your engine oil filter to do its job.

If the cooler plate is distorted and leaking contaminated oil then it seems to me the change frequency of the pre-filter would be rather high. It sure is much easier to change the main engine oil filter then it is to change the pre-filter due to location.

I have removed several cooler plates now to find the gasket has slipped between the sealing bosses. The plate(s) have had on average .003-.015" distortion. After cleaning I "rub" the surface on a granite plate with 800 paper to achieve near perfect flatness: .0002". Not once have I found the engine casting distorted, always the cooler casting. I always spray the new gasket with Permatex "High Tack" gasket sealer. Re-install the plate allowing a couple hours full cure before introducing oil. This reduces any future potential slippage of the gasket.

If this is a matter of changing the defective supply hose to the HEUI then I might agree, might as well provide additional protection if possible. Remembering the element is not the easiest to change due to location. Also, at what frequency do you change the element? Without a tell tale indicator of some type it is a guess as when to change. Starving the HEUI of supply oil due to a contaminated filter element is not a good idea for Mr. HEUI. This could cause various issues: air ingested into the common oil rail, low oil rail pressure causing IAP to ECM fault codes.........

It all comes down to the comfort level of each coach owner as to what provides peace of mind and understanding the risk(s) of adding new components.

Have a Great Day

I installed the IFS Filter kit last spring and everything worked out great.
Question for those who have replaced the gasket on the oil filter housing. Is it required to drain the coolant before removing? I have 2005 C7 engine.
Thanks in advance,
Don

pscatz69 · 01-26-2021, 03:03 PM

I also have a question.. When opening the top of their HUIE pump to inspect the coil, is there a gasket that needs replacing after loosening the top off?

Thanks in advance.

Cat · 01-26-2021, 11:30 PM

No the steel shim gasket does not need to be replaced. Just be aware of it and take your time clean and reuse.
Safe Travels

discovery39s · 01-27-2021, 10:04 AM

Quote:

Originally Posted by pscatz69

I also have a question.. When opening the top of their HUIE pump to inspect the coil, is there a gasket that needs replacing after loosening the top off?

Thanks in advance.

Be sure to clean the area around the HEUI spotless before opening the top.
Any piece of debris introduced has the potential of entering the system and usually heads straight for the injectors. I use brake clean myself to clean the surrounding surfaces. A pencil magnet works great to pull any metal away from the coil area indicating a potential issue.
Good luck

pscatz69 · 01-27-2021, 03:10 PM

Quote:

Originally Posted by Cat

No the steel shim gasket does not need to be replaced. Just be aware of it and take your time clean and reuse.
Safe Travels

Thank you CAT and Discovery for the answer. I am in the process of changing the water pump, cleaning both radiator and CAC and changing all sorts of things before I put the Rad back.

My other question is that I have a bit of oil coming out of the top of the HUEI pump (Connector) and wanted to inspect before putting all the other things back. The oil is not a gush but certainly is pushing out of the seal or even connector. If I continue to monitor would this be something okay to do?

Pat

Cat · 01-28-2021, 10:27 PM

Yes I would think this would be fairly easy. Make sure to buy the Cat seals for the fitting. It requires high temp and high pressure seal. The gasket for the top of the Heui cannot be bought through Cat. Maybe after market but I do not know of one.
If the head gasket is leaking (which is unusual) clean head area remove head clean steel gasket and use a Anaerobic sealant. Cat does sell this. Put very light coating on gasket reinstall.
While your there If you do remove the pump heui head do pull the oil using a vacuum tool and inspect the internal coil for metal flakes. If you flakes on the coil your pump is starting to fail. Good Luck

GS340 · 02-12-2021, 03:52 AM

Good morning. Does anyone know how often the new inline filter has to be changed?

I just had my second HEUI replacement and I have this new filter. The dealer tech said it was a screen and didn’t need to be replaced by me. Only if an issue were to come up. I’m confused by this

The CAT dealer tech did not replace the injectors. When they called me last week to say my no power issue is from a bad HEUI pump they said I needed all new injectors and the pump. Few days later they recommended NOT changing the injectors even though they found metal inside the pump. When I picked up the camper yesterday I brought up my injector/metal concern and the tech said he would not replace them. They cleaned the line and tested the injectors. They are firing correctly.

GS340 · 02-12-2021, 03:58 AM

Here are a few photos

The red circled part is the filter?

GS340 · 02-12-2021, 03:59 AM

This is the correct replacement filter?

https://www.mddistributorsstore.com/...in-line-filter

Cat · 02-12-2021, 11:59 AM

I will address not changing the injectors. It is not required to change injectors after a HEUI pump failure. If the engine still runs then the tech working on the engine is suppose to run cylinder cut out tests. If the injector pass this test then they are suppose flush line and replace the pump. In 50-75% of the time when the pump fails the injectors will need to be replaced. So it appears the tech followed the proper procedure, which is good to hear.
As far as the correct filter there are two available one is the OEM filter which filters oil before the Heui which is suppose to help prevent Heui pump failures. I do not have much faith in this filter because there different failure modes of the pump.
The second inline filter goes from the pump to the injectors. This filter was designed by a member of IRV2. Member discovery39s. Its purpose is to protect the most expensive part of a Heui pump failure, the injectors, and the labor to remove and flush everything. It wont prevent a Heui failure caused by oil issues, or premature wear of the pump, or other failure modes, but it saves you a considerable amount of money and time.
If you have the Oem filter then you can see it didn't prevent the HEUI failure and you were fortunate your injectors were OK. If you had discovery39s then the filter did what it was suppose todo.
So it depends on what filter you have. But I would change either filter after a failure. Safe Travels

IanSmith-UK · 02-12-2021, 02:22 PM

The filter pictured appears to be on the low pressure oil feed to the HEUI pump
It is not the after market IFS filter, which fits into the high pressure line between the pump and the injectors (perhaps basically described as a pot filter)

As such the filter pictured will not be protecting the injectors

Ian Smirh
Exeter, UK
2005 CC Allure 430 #31231
CAT C9 400 bhp #9DG02935

GS340 · 02-19-2021, 08:58 AM

Thank you to all for your quick replies.

The engine seems to be running very well even with the old injectors. The CAT Service tech originally said I needed to replace them but after he did more tests he called back and said to leave them. They're apparently the original injectors to the engine which means this is the 3rd HEUI pump for that set of injectors.