Lift Pumps and Exhaust Manifold

[Roy C Tyler]

Sitting down at Happy Trails in Surprise, AZ the last few weeks, I noticed a leak under the coach. I called Massey and they were able to get me in yesterday. I had the lift/fuel pump replaced in November of 2013 and this leak looked like it could be the same problem. Sure enough, one year and one month later, the lift pump was leaking again. Tom at Massey said it was the only one he had ever seen that went out that soon....just out of warranty.  They replaced the pump in 5 hours and just under $1000. During the replacement, they showed me that the exhaust manifold was broke in half. They told me I could drive it that way and when I get home, I will have it replaced. They did not have the time to work on it as they were booked up two months out. Tom said it would run between $1500 to $3500 to replace the manifold.  The guys at Massey are great and easy to work with. It is the only place to go if you are in the Phoenix area.

[Bill Sprague]

Roy,

I've had the same two failures.  My lift pump has lasted somewhere around 80,000 miles. 

The exhaust manifold cost me $2500 and was done by Valley Freightliner in Sumner, WA.  It took 16 hours.  There is no space to work and two of the bolts were broken and had to be drilled out. 

If it helps, your the third person I know that needed a new exhaust manifold. 

[Roy C Tyler]

Bill, thanks for the information.  The first lift pump I replaced last year lasted for almost exactly 5000 miles....very disappointing. When I get back home, I plan to start soaking the manifold bolts with WD40 before I take it over to Cummins West for the replacement.  Tom, at Massey in Phoenix, says he has seen so many broken manifolds on the ISC Cummins that he thinks they should have been recalled.  They are not made strong enough to handle the back pressure from the exhaust brake.

[Edward Buker]

Roy,

There are much better lubricants to help with breaking loose aged bolts and rusty nuts then WD40. When it comes to manifold bolts sometimes nothing will help. Some of the spray lubes foam a bit which helps work the lube deeper into the mating surfaces. These are offerings from CRC. I generally use their Power Lube, but look at Ultra Screw Loose (only used by crazy mechanics it would seem :-) and possibly Freeze Off in this link for manifold bolts.

http://crcindustries.com/auto/MS_Lubricants_Feb_2013_V3.pdf

Later Ed

[Richard McQuillan]

Bill Sprague, I think you might know 4 people that have had the broken/cracked exhaust manifold problem on the ISC 350. Mine failed at about 35000 miles and cost we about $1,700 to get replaced. I have been told that this is a very common problem of these engines.

[Joel Ashley]

I have to agree with Ed that WD40 is more of a lube and not the optimal penetrant, and CRC makes pretty good stuff.  Long ago and far away (ca. 1990) I spent weeks in our old barn trying to get the right side manifold off the 454 on our old Pace Arrow.  Eventually I succeeded, but WD40 was little help.  A foaming penetrant, incessant microvibrating the stud and block with a hammer and pin to work the penetrant in, and carefully drilling a straight hole for a bolt removal tool ultimately got the rear broken bolt out.  At least twice a day I'd go down to the barn, add foam and spend time tapping, and try turning the tool.  Imagine my elation when the day came that the damn thing finally cracked loose and twisted out, so I could take the warped manifold for resurfacing.  Not long after, I had a Banks Powerpack with headers put on and everything was cooler running.

With WD40 I might still be making trips to the barn LOL.  I had a similar issue with the clamp bolts on the exhaust pipes to that Pace after we moved here to the new house in '95.  I think I used PB B'Laster brand penetrant on that, and it's my go-to now for any rusted-in bolt. 

Joel

[Roy C Tyler]

Thanks everyone for the great information. When I get home, I will forget about the WD40 and go to my local Napa dealer and get some CRC penetrating solution to apply to the manifold bolts to help with their removal. Hopefully, with the use of some CRC product, the replacement of the manifold will be somewhere south of $2500.  Thanks again.

[George Harwell]

Roy, old 800495 has had the same illness over the years. I replaced the gasket in the lift pump but started leaking again so had a skinny kid at Cummins crawl under to install a new pump. Three hours later he reappeared looking like he had been in a cat fight but problem solved. I also found my exhaust manifold cracked at 75,013 and managed to change it myself mostly from above going through the bedroom access panel. Much to my surprise all bolts broke loose easily and we're not very rusty. Thanks to anti-seize compound the job went rather smoothly. Good luck!

[Gerald Farris]

The Cummins ISC engine from the mid 2000 model years is well known for exhaust manifold failures, including broken head to manifold mounting bolts. The same problem existed in the Cummins ISM engine in the early 2000 models. The problem is not the pressure from the exhaust brake (the ISM did not even have an exhaust brake), but it is caused by the manifold design not being able to withstand the heating and cooling cycles that it is exposed to. The rear engine motorhome installation is probably one of the most extreme applications for this heat cycling. The engine builders try very hard to balance the weight to durability issue, and sometimes they get a little over the line and durability is lost for the sake of light weight for better fuel efficiency.

Gerald     

[Dave Blystone]

I'm in the marine repair business and one of the best mixes for breaking loose frozein bolts is a 50/50 mix of acetone and transmission fluid.  We have used it many times with great success.
dave blystone
2001 patriot 33

[Gary Wolfer]

My 94 Safari Sahara had a isb cummins the exhaust manifold shrank so much it snapped 6 manifold bolts off at the block. Cummins made a replacement for the manifold that was split (two piece) in the middle for expansion. Probably if you ask they will have one for an isc as well. they may just replace it with oem to get rid of the old stock ask if they have a split manifold replacement. Also at most Napa stores you can buy a can of blaster which is excellent for frozen bolts also my grandfather used to tear down old saw mills years ago. He told me on J-bolts holding the structure to the foundation he used to pour coca cola on the nuts the night before.