$300 worth of ATF down the ATF down the drain!

[belfert]

The bad crimp on the hose is as much my fault as the hydraulic shop.  The hose was made a month ago and it turned out to be too long.  I had them cut the hose off last Friday and they didn't crimp the connector so I could check the fit.  At 4 PM Friday they told they would be open 8 am to 12 noon Saturday to crimp the connector.  I went over there at 9 AM Saturday and they were closed!  I ended up finding another hydraulic shop to crimp the end on.  It is that end that leaks.

I decided to pull the hose out this morning and get it over to the shop right away.  I found that the other end is also leaking, but just a tiny bit.  I don't think everything seated quite right on that end.  I didn't get anything done with the hose yet as the shop wants to see the fitting from the cooler.  I am hoping I don't have to pull out the intercooler and the transmission cooler as that is a full day job to remove both.

[belfert]

I don't know what would have changed that suddenly we can't run Dexron in older B500 tranmissions.  If it was okay in 1995 why not now?  I can understand why you must run Transynd in the new B500s.

The main reason I run Transynd is the extended drain interval.  I'm fairly certain the previous owner would have been using Dexron.  The first time you change to Transynd you are supposed to change after two years instead of four.  I waited four years anyhow.  The stuff I actually am using is Mobil Delvac Synthetic ATF.  It meets the same specs as Transynd and is Allison approved, but it is four or five bucks a gallon less than Transynd.

[JohnEd]

I'm just curious - how much pressure is this line that leaked under?  I have assembled hundreds of hose ends of different sorts and I have never had an end leak.  In particular a crimped on end - I don't do them myself, I get the hose shop to crimp the ends.  I just kind of want to understand how this failure happened so I can watch out for it.  The only thing I can think of is somehow the end that was put on was not designed for use with the hose type.

Brian

And you are the kind of guy that would share those findings with the rest of us.  Even if the first shop didn't actually crimp the badly leaking fitting, they did provide the specific hose and hardware.  Given that both ends are leaking and two different crimpers were used it seems a materials incompatibility or fitting hardware "flaw" should be eliminated.  Whatever they touched would now be suspect to me.  Kudos to their wanting to inspect the rest of the fittings and the shop crimps.  That is a confidence builder.  I think the leaking second fitting proves that they have a problem.  I would get those other fittings out but I weep for your lost labor and trashed schedule.

The shop isn't likely to have the equip to properly diagnose the cause of the failure.  I would want to see the shop express shipping the assembled fitting to the manufacturer of the hardware for "failure analysis" and a "Report".  Might get that done before you launch into ripping out the cooler and such....a days labor hurts.

Get on the web and Google the manufacturer of the fitting hardware and hose as well.  Might find a recall or other reports of problems.

Good luck and please let us all know.

John

[JohnEd]

I got a bulletin from Allison a couple years ago Dexron is no longer approved for use in the World transmissions neither is C-4

Yup you got it Clifford, that is why we run the high dollar Transynd. (trying to squeeze every last mile out of these short life trannys!)
  BK 

Just how short a life span do these things have?  In looking for a used bus would the 4 speed be worth more in terms of reliability and peace of mind?  I have heard more time than I can count "the Allison 740 is indestructible".

How do they live in service for your shop BK?

Thanks,

John

[Busted Knuckle]

JohnEd,
In all the years I've been around buses I have only had to replace one 740 due to failure and that was due to an incompetent driver who damaged the pan, had someone "patch" it for him, and forgot to refill the fluid to the proper level before heading off on a 200 mile trip.

He made it 150 mile before it locked up in drive!

We could start the bus and run it in neutral, but if we put it in gear it'd kill the engine.
I had a friend come haul it in to our shop. (I was on the road too with a different team, and actually came across "dumb driver" on the side of the road trying to pour 5 gallons of Co-op trans fluid in after it locked up!)

When the tow truck driver called me and asked "hey does this thing run at all?"
I told him "Sure, but it will die as soon as you put it in gear!"

He said "well I was hoping I could build air pressure, release the brakes, & let it roll backwards down the hill and back it onto the side road behind it where I'd be able to hook up and head back to the interstate w/o having to turn around after hooking up".

I told him go for it, it's already toasted!

Much to his and our surprise once he was barely rolling backwards he was able to stick it in reverse and it actually "broke loose and" pulled itself back around the corner to where he needed it to! (good thing too as he couldn't get the needed momentum just coasting)

Now that said I have replaced several multi-mega-mile 740's as preventive measures before they failed, but as said the dang things are damn near indestructable!

Now on the other hand in our coaches that have the B500 the 3 older models (2 '95's & '97) we have all had transmissions put in them not long before we bought them @ around 300,000 miles.

Now jump to the (2) 2005 models we have. One of them lost the trans @ 275,000 and the other is starting to act up @ 330,000.

Which is about par for what everyone has told us. (Even Sammy our truly beloved departed B500 guru had told me to expect to replace the B500's around 300,000!)

So there ya have it.
  BK 

[belfert]

And you are the kind of guy that would share those findings with the rest of us.  Even if the first shop didn't actually crimp the badly leaking fitting, they did provide the specific hose and hardware.  Given that both ends are leaking and two different crimpers were used it seems a materials incompatibility or fitting hardware "flaw" should be eliminated.  Whatever they touched would now be suspect to me.  Kudos to their wanting to inspect the rest of the fittings and the shop crimps.  That is a confidence builder.  I think the leaking second fitting proves that they have a problem.  I would get those other fittings out but I weep for your lost labor and trashed schedule.

The second leak is not a crimping failure like the first.  I think the second leak is due to the hose not seating down properly on the fitting.  I had one heck of a time even getting the connector started to screw it on.  I would like to find a 45 that has a JIC-16 male on one end and a JIC-16 male on the other end to make it easier to screw the hose on straight.

Once I get a new end on the hose I will have them test again to see if the other end leaks in their shop.

[JohnEd]

Thank you for the info.

Good luck with this.


John

[belfert]

I'm so sick of dealing with this hose crap that I didn't go right back out and put the hose in right away.  I really didn't feel like crawling back underneath again.  I delayed too long this evening and didn't quite get far enough to try starting the engine to check for leaks.  The mosquitoes got to me and I had to stop before I got all the ATF back in the transmission.

It took forever to run the reclaimed ATF through the paint strainer.  I can't really tell if the strainer is collecting any dirt or not.  ATF seems pretty thin compared to paint.

[belfert]

It works, it finally works!  I refilled with water (not coolant yet) and ATF and and started the engine and everything seems to be working!  I found a coolant leak, but tightening the hose clamp fixed that.  The hydraulic hose isn't leaking on either end as far as I can tell.

Okay, I do have a very minor ATF leak, but it is coming from the fitting the screws into the cooler.  I need to go buy another 1-1/2" wrench or find a pipe to put over the wrench to tighten that fitting.  (I had to cut my 1-1/2" wrench in half so it would fit elsewhere.)