DIY Water pump Bypass hose replacement, OM615, 616, 617
 

Changing the OM617 water pump bypass hose:

Disassembly:

#1. Loosen both clamps on the bypass hose.
#2. Loosen the radiator hose clamps at the thermostat housing, slide the clamp off the hose fitting area and tighten on the hose.
#3. Remove the radiator hoses at the thermostat housing.
#4. Remove the two thirteen millimeter bolts holding the thermostat housing to the cylinder head.
#5. A jolt/punch with the palm of your hand should separate the thermostat housing from the cylinder head.
#6. Remove the thermostat housing from the head.
#7. Wire brush the thermostat housing hose fittings until free from corrosion.
#8. Remove the bypass hose and clamps from the water pump.
#9. Wire brush the water pump bypass hose fitting until free from corrosion.
#10. Scrape the old gasket from the cylinder head and thermostat housing.
#11. Clean the threads on the two thirteen millimeter bolts that hold the thermostat housing to the cylinder head.

Reassembly:

#12. Install the bypass hose and clamps on to the water pump.
#13. Tighten the lower bypass hose clamp.
#14. Install the thermostat housing gasket on the cylinder head with dabs of permatex or your choice of alternative adhesive/sealer.
#15. Install the thermostat housing to the bypass hose and head.
#16. Install the two thirteen millimeter bolts holding the thermostat housing to the cylinder head.
#17. Tighten the two thirteen millimeter bolts holding the thermostat housing to the cylinder head.
#18. Tighten the upper bypass hose clamp.
#20. Install the radiator hoses at the thermostat housing.
#21. Loosen the radiator hose clamps from the hose, slide the clamp to the hose fitting area of the thermostat housing and tighten.
#22. Loosen the upper radiator hose clamp at the radiator.
#23. Slide the upper radiator hose clamp off the hose fitting area and tighten on the hose.
#24. Remove the upper radiator hose at the radiator.
#25. Use the upper radiator hose as a funnel to "back" fill the cooling system through the engine block.
#26. When coolant begins running out of the upper radiator fitting = the cooling system is almost full = stop.
#27. Install the upper radiator hose at the radiator.
#28. Loosen the hose clamp off the hose, slide the clamp to the upper radiator fitting area and tighten.
#29. Top off the coolant bottle.
#30. Test drive round trip 7 - 10 miles, and carry a gallon of pre-mixed coolant.
#31. Top off the coolant bottle.
#32. Monitor the coolant level and temperature for at least three days = you should open the hood at least two times per day, and carry a gallon of pre-mixed coolant.


Gasket, Thermostat Housing to Cylinder Head
MB# 616 203 02 80

Bypass hose….
MB# 900271 042012

Preventative maintenance note:
The following service should be done while the thermostat housing is off.
#A. Replace the thermostat if engine temperature averages higher than eighty degrees Celsius.
#B. Replace the three ten millimeter bolts (MB# 000933006123) holding the thermostat cover (they are known to corrode and snap with age).
#C. Replace any bad hoses and/or clamps on the cooling system.
#D. Flush the cooling system if it needs it.
#E. Check the breather tube (MB# 1152000058) is not blocked with lime/corrosion, replace as needed.
#F. If you have one: Check the mono valve diaphragm (MB# 0008350644), replace as needed.

Thermostat Seal, With Side-Hole
MB# 617 203 01 80

Thermostat, 80 deg. C°
MB# 617 200 18 15

Screw, thermostat cover (x3)
MB# 000933 006123

Breather tube, cooling system (water pump to head)
MB# 115 200 00 58

Seal ring, cooling system breather tube (water pump to head)
MB# 007603 008100

Mono Valve repair kit
MB# 000 835 06 44


PeachPartsWiki : OM617WaterPumpBypassHose
http://www.peachparts.com/Wikka/OM617WaterPumpBypassHose

When I look up the hose 900271 042012, it appears to be a bulk item. Is the part number for bulk or pre-cut? I'm sure one can figure out length easily once it is removed but just for info you might add the length to the procedure instead of just saying 'pre-cut'. Btw, from the parts search that is a 42mm ID x 54mm OD hose.

and part number for thermostat sealing ring should be thrown in as well.

i recently replaced my bypass hose, it kept leaking at the top until i really cranked down the hose clamp real good...when looking at the epc catalog it lists the hose as being 40mm not 42mm...i am thinking that's why it kept leaking...i have no luck finding a 40mm straight hose though..anyone else had this problem?

1983 300SD

Answer
 

The bulk hose is one meter long, and a higher price.

Each pre-cut hose is long enough for two OM615, 616, 617 engines, with roughly 13 MM left over.
* I cut it in half.
* Use the thermostat housing to test fit length.
* Then trim to a perfect fit.

Bypass hose….
MB# 900271 042012

FYI: This bypass hose is used on many MB engines with variable length dimensions.

OM699.001

OM698.200

OM697.001, 006, 051, 056

OM617.912, 913, 931, 932, 933, 950, 952,

OM616.910, 912, 913, 914, 917, 934, 936, 937, 938, 939, 940

OM615.940, 941, 944

OM366.965

OM353.911, 912, 913, 914, 950, 951, 954, 970, 971, 972, 978

OM317.201, 202, 203, 204, 206, 207, 208, 209, 214, 215, 216, 217, 218, 219, 220, 222, 224, 226, 228, 230, 231, 232, 233, 234, 235, 236, 240, , 241, 242, 243, 244, 245, 246, 247, 248

OM310.300, 301, 302, 303, 304, 305, 311, 312, 313, 314, 315, 316, 324, 325, 326, 327, 329, 340, 341, 342, 344, 345, 350, 386, 400, 401, 402, 403, 404, 405, 411, 412, 413, 414, 415, 416, 424, 425, 426, 427, 429, 440, 441, 442, 444, 445

OM309.300, 301, 302, 303, 311, 312, 313, 314, 315, 316, 324, 324, 326, 370, 371, 372, 373, 382, 390, 391, 400, 401, 402, 403, 404, 405, 411, 412, 413, 414, 415, 416, 424, 425, 426, 427, 429, 430, 431, 432, 433, 435, 440, 441, 442, 444, 445,

M117.960, 961, 962, 963, 964, 965, 967, 968, 982, 981, 982, 983, 984, 985, 986, 992, 993

M116.960, 961, 962, 963, 964, 965, 984, 985

M110.921, 922, 923, 924, 926, 931, 932, 981, 982, 983, 984, 985, 986, 987, 988, 989, 990, 991, 992, 994

M100.980, 981, 982, 983, 985

Answer
 

Thermostat Seal, With Side-Hole
MB# 617 203 01 80

Gasket, Thermostat Housing to Cylinder Head
MB# 616 203 02 80

Thermostat, 80 deg. C°
MB# 617 200 18 15

Here are some part numbers for bulk hoses that works and can be cut to size from your local parts house.

Goodyear PN# 56026 (I.D. 1 5/8 inches or 41.275 mm)
Gates Green Stripe PN# 4168-08041 (I.D. 1 5/8 inches or 41.275 mm)


This is a 40mm hose I found in the Gates catalog..
Gates Flexcord Plus PN# 4272-10400 (I.D. 1 9/16 inches or 40 mm )





.

sweet..thanks deliveryvalve

Can anyone tell me the torque spec for the two 13mm bolts holding the housing to the block? I have everything ready to go back together but don't want to overtorque those bolts and haven't had any luck finding the numbers.

Er no not yet! Chap 05-115 doesn't have it - neither does Haynes... I've got a German FSM that I can check once I get a Windows operating system up and running somewhere. I'll check that at some time this week (I need it for other stuff too!).

Thanks! One of these days I need to pick up a print FSM for the om616, but it seems whenever one pops up on eBay (or in the parts forum) it goes in a snap. I have an AllData disk somewhere but I haven't been able to find it ... I'm sure it's in a CD case somewhere ... :rolleyes:

Clean vs. replace by-pass pipe?
 

Has anyone been successful at cleanig the by-pass pipe vs. replacing it?

I'm refeffing to MB part 1152000058 -- picture is above in a previous post.

Answer
 

Yes, but it is a pricey tedious mess, generally takes 2-3 weeks soaking in various Lime/corrosion solvents + daily cleaning attempts with pipe cleaners, wire, etc.
The last one I salvaged cost $30.00 or more in solvents.

Cider vinegar
Lime-A-Way® Tile Cleaner
CLR Calcium Lime & Rust Remover
Urnex dezcal activated scale remover
ZEP PROFESSIONAL Calcium & Lime Remover
Mirachem 250 Rust & Scale Remover

NOTE:
If anyone finds a effective/cheap, easy way please let me know.

After a big delay I can say - sorry! I still can't find it even in the German FSM. Perhaps it is just one of those black holes of knowledge that will never be filled?

it's a grade 8.8 8mm bolt. usually the torque on a bolt with those specs is 18-22Nm. 13mm is just the head size of the bolt.
that being said, i could also not find the factory torque spec. after i cleaned the threads in the head and the threads of the bolt, i torqued mine to 22Nm and have not encountered any leaks or problems as of this writing. 617.952 engine.

as far as the hose: i needed to replace mine, so i stopped by a local NAPA and asked if they had any radiator hoses that had been cut for other applications (they often trim hoses and keep a box of the left-over pieces). i got a 777 hose (NAPA part number on the sticker) and it fit very well. the small end piece i got had enough length to replace the hose 2 times. the best part was that i got the piece for free. i don't know the application or length of a 777 hose, but it might be inexpensive to buy one and have a bunch of spare hose just in case.