Coolant hose gasket change - 5.9 L 2nd Gen. Dakota
 

I have 2002 Dakota Quad Cab SLT 2WD with the 5.9L. Coolant leaking at the hose gasket near the engine block where I assume the thermostat is. Want to change the stat and gasket myself. Seems like the A/C compressor is in the way when trying to remove the thermostat housing at the end of the hose.

Any advice on how to do this the easiest way would be appreciated. Do I have to loosen the compressor bolts? (tried a quick search but if there's a post on here, could use the reference.) Thanks.

all i did was take the Tstat housing off and put in a new one. Just drain the coolant cause i made a mess. thought someone said it leak a LITTLE and that wasnt a little lol

I had to finesse (not what i do best) to get the housing out but it did it fine. I have the 3.9 w/ac but it went. OH and I didnt take the hose off the housing, i just zip tied it to the hood :)

Id drop in a 180 tstat while your at it too. Mine was in the $10 range form napa. just a thought

You can remove the alternator/AC bracket and swing it out of the way. Check the housing, as it may be rusted and need replaced (mine was). Also, make sure the gasket surface is as clean as possible, and get the $1 tube of gasket sealant up at the checkout.

RE: 2002 Dakota 5.9 L thermostat replacement:

OK, unfortunately, I see that I have to swing the Alternator/AC bracket out of the way. (The "FRONT" tab on the thermostat housing looks like the only problem, otherwise the housing would pull right up).

I can't see exactly where and how many bolts there are to loosen the Alternator/AC bracket. Any help identifying all of the bolts would be apprecitated. Thanks in advance.

Here's the instructions from Chilton's:
1. Locate thermostat
2. Disconnect negative battery cable
3. Drain the engine coolant from the block until the level is below the thermostat
4. (V-10 specific)
5. On most V-6 and V-8 models the alternator must be removed or repositioned for access to the thermostat housing
6. Remove the radiator hose from the thermostat housing
7. Disconnect any sensors fitted to the thermostat housing (which you would think Chilton's would name specifically)
8. Remove the retaining bolts from the thermostat housing. Note lengths of each for ease of installation
9. Remove the thermostat housing, thermostat and gasket, if fitted
10. Note the relative positions of all components, especially gaskets and seals. Note the orientation of the thermostat in the housing.

To Install:
11. Be sure the new thermostat (this is replacement instructions) is the correct one for your engine
12. (V-10 specific)
13. Clean the gasket or seal mating surfaces
14. Paper gaskets must be replaced
15. Install the thermostat, gasket or seals
16. Install the thermostat housing on the engine
17. Be sure all components are properly sealed before tightening
18. Tighten the housing bolts to 18 ft. lbs. Fasteners should be tightened evenly to avoid leaks or damage
19. Reinstall the radiator hose onto the housing
Note: ensure that you ve secured the system drain plug(s) before refilling with coolant
20. Refill the radiator with a proper coolant mixture
21. connect the negative battery cable
22. start the engine and bleed the coolant system
23. Ensure the thermostat is operational (by checking the upper radiator hose for warmth) and that there are no leaks.

They don't mention putting the alternator back in place for some reason. Chilton's isn't the best, I'm sure, but you get the gist. Good luck.

I just replaced the water pump on my '98 5.9L (bad bearing) and also replaced the thermostat.

You can get the thermostat housing off by just moving the alternator a bit out of the way but you cannot clean the gasket surface on the manifold side properly. Mine needed a lot of cleaning since it had not been apart since 1998. To do that the alternator, AC compressor, and accessory bracket neeed to come off. I think there are about 7 bolts holding the bracket on (separate from the water pump bolts). Once all these parts are out of the way you have good access to the manifold for gasket removal. I used Permatex gasket remover, razor blades, and a good gasket scraping tool (carefully). A die grinder air tool with 1" scotch brite pads did the final clean up. A lot of work to just get at the thermostat!

Barry

Id drop in a 180 tstat while your at it too. Mine was in the $10 range form napa. just a thought[/quote]


dont this if you use this truck for the winter, as your heat will be colder, and MPG will suffer... but performance will increase

haha when I got my 5.9 I had to replace the water pump, and thermostat housing, and the hose I also threw in a 180 while I was there.