Water pump replacement

Stant 10233 looks like the same pattern but is 1.1 bar (16 psi) instead of 1.6 bar. 30% glycol, distilled water, water wetter gets a boiling point of about 268 F. And the maximum pressure to open the cap drops by 30+ percent. Once they start leaking you're hosed. So the plan is to get under the seal failure pressure. A 13 psi cap would be about 259 F. I haven't found a 13 psi (.9 bar) replacement as stant doesn't seem to make one. 0.9 bar is 56% of 1.6 bar. I suspect there's one out there someplace.

Stant 10227 seems to be .9 bar version. So I ordered one.

baggerman said:

Stant 10227 seems to be .9 bar version. So I ordered one.

Click to expand...

Let us know if there's any issues when you change it out

Also ordered a 10227.
Put it on and report back

The 10227 showed up yesterday. Same pattern fits perfectly.

aque0us said:

Yeah, no choice when racing, it's yelled "HIGH" at me for 6 laps before lol. Tried the Graves 2.0 cap, same ..... Got Motul "MoCool" in there now vs Cool Aide which I find to be too powdery and cakes when blown out for lack of a better word, cant use glycol based coolants. VP makes a non glycol coolant, might try that.

Here's one from the Fall.

Click to expand...

What radiator are you running?

I need to go back and see where "high" turns on. But it's way up there 290 F ?. Really hard on the motor. Softens the heat treating of the heads etc. I'm surprised it didn't lose a head gasket. Do what Steven has done and go to the big radiator. Way cheaper than another motor.

Both seem to be $5K and I don't think you can run fans with the big radiators...either way if the dash indicates high I'd bow out. If you're a sponsored (ie professional) racer I suppose that's another thing.

ETA: The Febur looks to be $3.7K.

stock, and yeah the whole fan thing is an issue for me, 7k track miles and still goin strong

My H20 is running a fan.

If you order your H20 directly from these guys:


They can sell you one already provisioned for the OEM fan.

I ordered my H20 from Bellissimoto, and was unaware until I received it that it did not come provisioned with brackets to hold the OEM fans.

I was disappointed, but then, on a whim I emailed Galletto directly to ask about making one for me with the fan brackets built in because their website says they can custom make any radiator to spec. They responded very quickly saying it wasn’t a custom piece, because they had them in stock with the fan brackets but only typically sell them in Vietnam and Indonesia where it’s so hot that street riders want the H20 even for riding in stop and go traffic.

They shipped me one for the same price as the non-fan provisioned radiator.

The OEM setup has two fans, while the H20 is only provisioned for one fan, so you only transfer one of the OEM fans over, and that’s more than enough to keep it cool even stopped in traffic on the street on a very hot day.

auqueOus no way I’d race in the summer at Chuckwallah without an bigger radiator, unless you have a backup bike standing by to keep your weekend from going down the ......., and even so…

Nobody races in the summer, it’s a winter series. First and last rounds are the ones you have to watch out for. Thanks for your input but she hasn’t let me down for 3 years and 7k miles now. We have about 8 V4s on the grids and we are all doing just fine with the stock set up, some who crash more even running Chinese aftermarket XD. My point was that these bikes are meant to be ridden, not pulled over when they hit 4 bars. Come on down and you can bring up the back of the grid with your H20

aque0us said:

Nobody races in the summer, it’s a winter series. First and last rounds are the ones you have to watch out for. Thanks for your input but she hasn’t let me down for 3 years and 7k miles now. We have about 8 V4s on the grids and we are all doing just fine with the stock set up, some who crash more even running Chinese aftermarket XD. My point was that these bikes are meant to be ridden, not pulled over when they hit 4 bars. Come on down and you can bring up the back of the grid with your H20

Click to expand...

You had me until the end

Challenge accepted lol

(I think this won’t go well for me hahaha)

Aluminum if heat treated typically between 200 C and 250 C (depends on specific alloy). Because of the use Ducati must be treating the heads to T7. This uses a quenching step to create the end condition. The "high" light turns on at 166 C and the range runs to 200 C. You can also anneal aluminum starting at about 200 C. I'd be pulling the heads off the one you ran for multiple laps on high.

For the protection of the water pump, an interesting approach is to use the Stant 10227 to reduce the pressure in the system. However, higher pressure in the cooling system raises the boiling point of the coolant to decrease the risk of overheating. The Panigale seems to have an issue with high temperatures. Perhaps Ducati chose the 1.6 bar pressure setting for a reason. I am curious to see the first practical experiences with the 0.9 bar cap.

Yup, sticking to the stock 1.6 cap instead of the 2.0 graves this go around.

The 0.9 bar gives a boiling of about 260 F. The fourth bar lights at 239 F. I think a lot of the water pump failures occur during heat soaks. Since I turned on the fourth bar following a road construction guide car at 100 degrees I think if one were to turn the bike off when the 4 or 5th bar is showing bing there goes the waterpump seal. Seems impossible to me it's a material incompatibility thing. Really old tech. So they miss sized the shaft diameter and seals at the low end of the seal face load tolerance leak when the system pressure is too high. Once they leak you're done seal needs to be replaced.

Pulling the plastic thermostat and installing the cbe housing also helps with controlling temps. There's no longer a restrictive valve in the engine waiting on a temperature rise, for the cooling system to turn on

Ducati put out a service bulletin for this to replace under warranty or should we open a class action lawsuit to get it replaced?

Can someone explain what increasing the Pumps shaft diameter has anything to do with the radiator water pressure and weak pump seals ??


I have had 3 water pumps go on my 2018 V4s track bike and was told my 4th pump was rev 7 !!!
I also never had any high temperature signs, as the dash stayed in its normal zone

Obviously I sold the bike in 2023 after that 4th pump was installed as I had no confidence in the engine and didn't want to get fluid on my back wheel, I was looking at the new model but Ducati wouldn't tell me what was causing the pump to fail....

I do like the temporary fix of adding fluid pipes to the output of the pumps scavenge ports - saves crashing for sure, but still only a plaster on the problem

Even with the 2025 model, the engine is basically the same, what makes you think they have changed the pump design ?!?!?!?!