P700 2017 P700-2 Antifreeze leaks around head gaskets.

[Deluxe700]

Well several folks have been asking me about this...so I am going to try and do a write up.. I actually found the "old" gasket that came out, and then I started remembering what the issue really was and the steps I did to fix it...This is for a coolant leak at the thermostat housing leaking down by the cylinder...
PICTURE OF THE GASKET BELOW. YOU CAN CLEARLY SEE THE MISSING RUBBER..THIS IS WHAT CAUSES THE LEAK. -- I think it is a defect from the factory. The missing piece is cut out so precise..not like it was pinched or something.
So here goes my best at the write up:
1. Cold engine
2. Remove radiator cap (not sure if this is necessary, but I did)
3. Remove the air intake from the airbox so that it is out of your way.
4. Remove the black plastic left hand side cover so you can get to the thermostat housing on top of the engine.
5. Get rags and stuff down around the bottom of the cylinder and anywhere you can get them to catch the fluid.
6. Remove the 8mm bolts that hold on the t-stat housing ( be careful not to drop). Coolant will begin to leak out as you are removing.
7. Move the top part of the housing out of your way.
8. Now you can see the t-stat and gasket. Remove the t-stat. Notice how it is sitting in there with the bleed hole lined up with the notch or hump on the outside of the housing. You will see what I'm talking about when you open it up.
9. There may be some residue so, Clean the top of the housing where the gasket sits and the bottom housing where the gasket sits.
10. Remove the old gasket from the t-stat. The gasket has a grove and slides into the t-stat.
11. Pour some coolant on the new gasket and slide it on the t-stat
12. Gasket part number for a 2017 P700 (probably same for other years, but check): HONDA OEM 19305-KV3-010
13. Replace t-stat in housing making SURE to LINE UP THE BLEED HOLE WITH THE NOTCH ON THE HOUSING. Make sure the gasket sits flush with the housing base.
14. Replace the housing bolts and tighten to 9 ft lbs. Go easy remember its aluminum.
15. Replace lost coolant. Fill radiator to the top and put rad cap on.
16. On top of the t-stat housing is the "bleed" screw 10mm. Loosen this up. If you have a new copper sealing washer then put a new washer on it and screw it back in a little, but not all the way.
17. Start engine and watch the bleed screw. Rev it up a few times during this warm up period. Keep watching the screw. You will see bubbles
18. When you see a steady stream of coolant, then screw the bolt in and tighten to 9 ft lbs.
19. Wipe up all the spilled coolant and let it continue to warm up. Watch for any leaks...You should not have any.
20. You are done and your problem is solved.

 

[Deluxe700]

Well several folks have been asking me about this...so I am going to try and do a write up.. I actually found the "old" gasket that came out, and then I started remembering what the issue really was and the steps I did to fix it...This is for a coolant leak at the thermostat housing leaking down by the cylinder...
PICTURE OF THE GASKET BELOW. YOU CAN CLEARLY SEE THE MISSING RUBBER..THIS IS WHAT CAUSES THE LEAK. -- I think it is a defect from the factory. The missing piece is cut out so precise..not like it was pinched or something.
So here goes my best at the write up:
1. Cold engine
2. Remove radiator cap (not sure if this is necessary, but I did)
3. Remove the air intake from the airbox so that it is out of your way.
4. Remove the black plastic left hand side cover so you can get to the thermostat housing on top of the engine.
5. Get rags and stuff down around the bottom of the cylinder and anywhere you can get them to catch the fluid.
6. Remove the 8mm bolts that hold on the t-stat housing ( be careful not to drop). Coolant will begin to leak out as you are removing.
7. Move the top part of the housing out of your way.
8. Now you can see the t-stat and gasket. Remove the t-stat. Notice how it is sitting in there with the bleed hole lined up with the notch or hump on the outside of the housing. You will see what I'm talking about when you open it up.
9. There may be some residue so, Clean the top of the housing where the gasket sits and the bottom housing where the gasket sits.
10. Remove the old gasket from the t-stat. The gasket has a grove and slides into the t-stat.
11. Pour some coolant on the new gasket and slide it on the t-stat
12. Gasket part number for a 2017 P700 (probably same for other years, but check): HONDA OEM 19305-KV3-010
13. Replace t-stat in housing making SURE to LINE UP THE BLEED HOLE WITH THE NOTCH ON THE HOUSING. Make sure the gasket sits flush with the housing base.
14. Replace the housing bolts and tighten to 9 ft lbs. Go easy remember its aluminum.
15. Replace lost coolant. Fill radiator to the top and put rad cap on.
16. On top of the t-stat housing is the "bleed" screw 10mm. Loosen this up. If you have a new copper sealing washer then put a new washer on it and screw it back in a little, but not all the way.
17. Start engine and watch the bleed screw. Rev it up a few times during this warm up period. Keep watching the screw. You will see bubbles
18. When you see a steady stream of coolant, then screw the bolt in and tighten to 9 ft lbs.
19. Wipe up all the spilled coolant and let it continue to warm up. Watch for any leaks...You should not have any.
20. You are done and your problem is solved.

View attachment 62612

Glad this write up helped to all the folks that PM'ed me...Glad to help !!

 

[jinx]

We have a 700 as well. Haven't had this issue so far but now have a good explanation of how to fix if/when we do.
Thanks for taking the time to write it up

 

[Mudwing]

@Deluxe700, how much coolant did you use to fill after the repair?

 

[Deluxe700]

@Deluxe700, how much coolant did you use to fill after the repair?

Not sure exactly in ounces...I know it was less than a quart of the Pro Honda HP Coolant... Once I got the "fix" done...I just went up front and filled up the radiator...then bled the system....then topped off...but I know it was less than a bottle of the Honda HP Coolant, quart.

 

[William]

This thread has really kicked my ocd into high gear! I have checked every hose on my bike... no leaks...

 

[Deluxe700]

This thread has really kicked my ocd into high gear! I have checked every hose on my bike... no leaks...

Don't worry...most coolant leaks are easy to fix and nothing major..

 

[Mudwing]

I’m adding pics to @Deluxe700 ’s write up. He’s right about the precise cut in the gasket from the factory, bad design. Super easy fix! Top pic is showing the bleed hole lined up with the notch.

 

[Deluxe700]

@Mudwing ... nice pics...good addition to the write up..

 

[Harman24630]

What is the part # for that o-ring?

 

[Mudwing]

19305-KV3-010 Honda

 

[Neohio]

What is the part # for that o-ring?

found under the cylinder head parts fiche.

 

[DG Rider]

Sometimes those gaskets have cutaways for features on the t stat like that. Almost looks like they used the wrong part.

 

[Elitebowman]

Well several folks have been asking me about this...so I am going to try and do a write up.. I actually found the "old" gasket that came out, and then I started remembering what the issue really was and the steps I did to fix it...This is for a coolant leak at the thermostat housing leaking down by the cylinder...
PICTURE OF THE GASKET BELOW. YOU CAN CLEARLY SEE THE MISSING RUBBER..THIS IS WHAT CAUSES THE LEAK. -- I think it is a defect from the factory. The missing piece is cut out so precise..not like it was pinched or something.
So here goes my best at the write up:
1. Cold engine
2. Remove radiator cap (not sure if this is necessary, but I did)
3. Remove the air intake from the airbox so that it is out of your way.
4. Remove the black plastic left hand side cover so you can get to the thermostat housing on top of the engine.
5. Get rags and stuff down around the bottom of the cylinder and anywhere you can get them to catch the fluid.
6. Remove the 8mm bolts that hold on the t-stat housing ( be careful not to drop). Coolant will begin to leak out as you are removing.
7. Move the top part of the housing out of your way.
8. Now you can see the t-stat and gasket. Remove the t-stat. Notice how it is sitting in there with the bleed hole lined up with the notch or hump on the outside of the housing. You will see what I'm talking about when you open it up.
9. There may be some residue so, Clean the top of the housing where the gasket sits and the bottom housing where the gasket sits.
10. Remove the old gasket from the t-stat. The gasket has a grove and slides into the t-stat.
11. Pour some coolant on the new gasket and slide it on the t-stat
12. Gasket part number for a 2017 P700 (probably same for other years, but check): HONDA OEM 19305-KV3-010
13. Replace t-stat in housing making SURE to LINE UP THE BLEED HOLE WITH THE NOTCH ON THE HOUSING. Make sure the gasket sits flush with the housing base.
14. Replace the housing bolts and tighten to 9 ft lbs. Go easy remember its aluminum.
15. Replace lost coolant. Fill radiator to the top and put rad cap on.
16. On top of the t-stat housing is the "bleed" screw 10mm. Loosen this up. If you have a new copper sealing washer then put a new washer on it and screw it back in a little, but not all the way.
17. Start engine and watch the bleed screw. Rev it up a few times during this warm up period. Keep watching the screw. You will see bubbles
18. When you see a steady stream of coolant, then screw the bolt in and tighten to 9 ft lbs.
19. Wipe up all the spilled coolant and let it continue to warm up. Watch for any leaks...You should not have any.
20. You are done and your problem is solved.

View attachment 62612

Hi, I just bought a Honda Pioneer 700. It is a 2018. It only has around 300 miles on it. I smelled anti-freeze last week one day, and today I did too. I noticed I am low. So I will be looking my machine over tomorrow. Honestly, I have no clue about this machine. I have only owned a Honda 1991 Fourtrax 300. So I will have to look this over. Thank you for writing this, something for me to look into.

 

[Mudwing]

Hi, I just bought a Honda Pioneer 700. It is a 2018. It only has around 300 miles on it. I smelled anti-freeze last week one day, and today I did too. I noticed I am low. So I will be looking my machine over tomorrow. Honestly, I have no clue about this machine. I have only owned a Honda 1991 Fourtrax 300. So I will have to look this over. Thank you for writing this, something for me to look into.

Before you tear into it, try and locate the leak. Check all hoses for tightness. I noticed dried antifreeze on the block when mine leaked.