HELP!!! Bypass valves

[rogers]

Help me please!!! I am rebuilding a 599 block to replace a 141 block. The machine shop removed the oil filter/cooler bypass valves when they machined the block. So I ordered some new from gm. I got two different part numbers and sizes. The part numbers are 25014006 and 25161285. Part number 25161285 fit great in the hole closest to the block and is covered by a kind of freeze plug with a hole in it (see picture #3). However neither valve fits in the hole furthest from the block. I am at a loss, these were the only part numbers the dealer could find.

So the question is where do I get the right size valve?? Do I need a valve? Is there some kind of spacer or collar?

Please help, I need this back on the road ASAP!!

[rogers]

So, I guess everyone already knows about all this and that is why no one has responded to my plea for help. However, in case this might help someone else, it has been posted here in the 6.2/6.5 assembly tips. Thanks for all the help on this.

[EWC]

Check these out on Ebay 120332731046

[Robyn]

Do you have the original valves that the shop removed??

There may have been a change during the model years????? just as the size of the cooler in and out fittings in the block changed size.

I have never removed these. I take care to keep crap out and then wash things well with hot water and soap and bow out well prior to reassembly

Just checked the GM shop manual on this stuff.

The one valve is the filter bypass valve and it just presses into the block. The other one is the cooler bypass valve and is retained by the cup plug.

The book does not show the one retained by the plug though, just mentions it.

See if you can get the old ones back for reference.


Robyn

[bypassvalve]

I dont know what i would have done without your posts, i've called and dropped by multiple GM dealers, hounded my lame ass machinist (who lost the OE), and part store to NO AVAIL looking for a filter bypass for the 599... I kept ending up with the same 3 part numbers that didnt fit... I saw your post, and this one guy on ebay sold me his last one. Not one store in the US or online could get they're hands on it!

after three weeks of dead end research... i hope to god this one fits!!!

I cant message you directly, but if you see this im extremely grateful!

I got a couple more questions for you if you're still on here, and i'll send you a bottle of California wine if you want it!

super HELLA STOKED!
-David

[More Power]

I dont know what i would have done without your posts, i've called and dropped by multiple GM dealers, hounded my lame ass machinist (who lost the OE), and part store to NO AVAIL looking for a filter bypass for the 599... I kept ending up with the same 3 part numbers that didnt fit... I saw your post, and this one guy on ebay sold me his last one. Not one store in the US or online could get they're hands on it!

after three weeks of dead end research... i hope to god this one fits!!!

I cant message you directly, but if you see this im extremely grateful!

I got a couple more questions for you if you're still on here, and i'll send you a bottle of California wine if you want it!

super HELLA STOKED!
-David

Oil bypass valves are a topic that I've not fully investigated or fully understood. I do know that the two 6.5s I've had rebuilt did not have their bypass valves removed during the block prep at the machine shops. Yes, the engine machine shops dipped the blocks (or cleaned them very well), but none of oil bypass valves had been removed during the process. In fact, whenever I finally get a good crankshaft, I'll be assembling another 6.5 that had its block cleaned by a pro rebuild shop. That block never had its oil bypass valves removed either... So...

Maybe... it's only when a block is cleaned by heat does it need to have its oil bypass valves replaced. I don't know, but I'll be looking for answers in the short term so I better understand what we need to know about oil bypass valves.

[Robyn]

My only experience with replacing valves came when I scored the new AMG block I found with unfinished bores.

That block had zero plugs, fittings, dowels, a real honest BARE BLOCK.

Normal cleaning methods used to clean blocks can be done quite well without removing the two valves.

Here are the factory part numbers for the valves.

The filter bypass is #25014006

Cooler bypass is #25161285

[Robyn]

VALVES LISTED ON EBAY.

http://www.ebay.com/itm/Genuine-GM-B...VZATvV&vxp=mtr