Water pump cover plate stuck

[Iceni John]

For several days I've been trying to remove the non-metallic cover plate from the coolant water pump so I can check the impeller for wear and check its nut is tight.   I've scraped all around the groove the C-clip sits in to clean out rust, I've sprayed Liquid Wrench all around the groove, I've whacked the cover's four protruding bumps with a rubber mallet and block of wood (I don't want to hit them too hard because they're not metal), and the darn thing still won't budge.   I'm guessing it's stuck to the O-ring inside.

Any tips on getting this cover off non-destructively?   It's really frustrating when a "simple" job turns out like this.

Thanks, John

[Gary Hatt - Publisher BCM]

An impact wrench may work, but it may also break off the screw.  If you can get to it and it is a hex head screw, you can always use a cold chisel to catch one corner of the hex head and with a hammer try to pound the screw head several times so it turns counter-clockwise. This too may break it off too, but at least you should be able to see what is going on a bit better than an impact wrench that covers the entire screw head.

A smoke wrench may work too, but only if you can get to it without starting something on fire.  By heating the housing it should free up any rust which almost always works but may ruin the O-ring.

There are better penetrating oils out there than Liquid Wrench.  Cliff told me about one recently so maybe he can chime in.  If you have a week or so to soak it daily, I would start with that approach as I personally hate having to drill out broken bolts. 

It may be best to remove the entire unit and drain the coolant, which will act as a heat sink if you try to heat it then use the smoke wrench to un-freeze the bolt and it should squeak right out.  Then use Never Seeze when you assemble it so the next time it will come right out.

I am a big advocate of Never Seeze and I recommend every 5 years that you completely dis-assemble your bus and put it back together using Never Seeze on every bolt then you should never have any problems removing any parts thereafter. It takes about a gallon.

[luvrbus]

I spray Lime Away around the edges then tap in the middle a few time then tap on the tabs changing direction from side to side then it falls out hits the concrete floor and chips,it will come out fairly easy once you break the build up away   

good luck   

[Iceni John]

Hi Gary!

The cover plate I have is a non-metallic material, maybe a fiber-reinforced plastic of some sort or perhaps a molded laminate material, I don't know.   For this reason I can't break out the BFH to encourage it to move.   This plate is held in place by a big internal C-clip, not the easiest to remove and replace.   I'm assuming it's never been removed since the bus was born, so it's probably fused to whatever's inside.   If I had some way to measure the flow rate from the pump I would know if the impeller is OK, but I don't so I have to look at it to see if there's any cavitation wear.   I'm completely redoing my entire cooling system now  -  it would be silly to not inspect it at this time.

Thanks, John

PS  -  You missed a fun Buses Gone Wild get-together this year.   All the usual suspects and more, including someone who owns two Embree Crowns!   This year's BGW was in memory of Glen Torrey from Mojave (he had six Crowns and a Gillig) who passed away earlier this year.   We'll all miss him.

[Iceni John]

I spray Lime Away around the edges then tap in the middle a few time then tap on the tabs changing direction from side to side then it falls out hits the concrete floor and chips,it will come out fairly easy once you break the build up away   

good luck   

Great suggestion!   I'll try that today.   I just don't want to whack the plate too hard in case it cracks.

Many thanks, John

[Gary Hatt - Publisher BCM]

John,

If it is a non-metallic cover plate, I would consider sacrificing it and making a pattern and have a new one made up at a sheet metal shop.  Most of them should have nibblers that can remove the outside material very quickly or if you are a back yard mechanic you can make your own with a grinder if you have enuf time.  The advantage of destroying it is that you will be able to remove the non-metallic material then you can get a good pair of vice grips on the base of the bolt where you have more leverage and you should be able to turn it out.

Or you can probably even make a new non-metallic cover if necessary. 

I didn't know about the BGW rally this year, as nobody sent me an announcement to post in the magazine, on our website or on our Facebook page. If someone would send me some pix and an article to publish then I may get even more excited and try even harder to make it next year. 

[Geoff]

I always manage to get the Clip offf by tapping the holes at the end with a small round chisel until.I can shove a small screwdriver in the edge and work the C clip out.

[Iceni John]

I always manage to get the Clip offf by tapping the holes at the end with a small round chisel until.I can shove a small screwdriver in the edge and work the C clip out.

I got that clip off, not easily, then had to buy another circlip pliers to put it back on temporarily while I think how to free up the plate.   I would have never guessed that such a simple piece of Detroitus could be such a PIA to get off!   I'll try Luvrbus's idea of CLR or Lime-Away, or toilet bowl cleaner, or C4, or whatever works.

Aren't buses fun?

Thanks, John 

[niles500]

Did you call DD to see how much the plate is, I'd replace it - FWI

[chessie4905]

Clean the plate with some lacquer thinner and gorilla glue three or four dowels stubs to it. Then pull on them after the glue dries. You'll need to use tape to hold them in p!ace till the glue sets. You can cut most of them off after you get the cover off with a dremel. The rest with a bench grinder

[Boomer]

John, do you know what became of the ex Grand Teton Crown tour bus, the blue one that Glenn Torrey had?  Is it still there, or?  Sorry for the off topic.

[Geoff]

The 4 protruding nubs have threaded holes in them.  Do you have a slide hammer that holds a screw?

[oltrunt]

When I first got my MCI9 8v92 I had intermitent over heating problems.  The radiators were fresh recores, the fan worked properly, the thermostats were new and all the rubber seals around the radiators were good.  But when I pulled the plastic cover off the water pump I found the impeller free to spin on it's shaft as the nut had worked loose.  I replaced the nut and washer and never saw the engine over heat again.

Long story longer, don't give up on inspecting the impeller.  Jack

[luvrbus]

Those 4 lugs are to use a big pair of channel locks on to twist the cover to break it loose.I do it that way sometimes when they are really stuck, I never saw one that was threaded on the lugs Geoff 

[Geoff]

I seem to remember holes in the nubs.  If not, I welded vice grips to a nut that fits my slide hammer.

--Geoff