S60R 2004 – falling fuel pressure

nzxtnzxt · Post by **nzxtnzxt** » 23 Aug 2025, 10:46

Hello, pressure loss after turning off the engine. I checked that the pressure is escaping through the valve shown in the photo. I disconnected the return hose from the pump, installed a tube and held it with my finger, turned the key in the ignition and observed the pressure parameters in Vida to check if the pressure was dropping. It remained at 400 kPa, and after connecting the hose to the pump and turning the key, it dropped very quickly from 400 kPa. Now my question is: has anyone dismantled this device (valve)? There are different versions, I have even seen a U-shaped cotter pin. I think mine is permanently attached or glued.
Another issue is that I cannot perform a pump test on the display, which shows kPa values. I only see dashes, and when I press the button, nothing appears, nothing changes, the function does not work.In photo no. 2, the values are marked in red and I have lines, but I don't have any values, nothing is showing — this is an example photo.

Post by **cn90** » 23 Aug 2025, 11:27

What are the original symptoms?

nzxtnzxt · Post by **nzxtnzxt** » 23 Aug 2025, 11:33

The symptoms are that it takes a long time to start, or you have to turn the ignition key several times, or it takes a long time to start,In addition, it does not reach the required pressure set by the controller.

Post by **cn90** » 23 Aug 2025, 11:39

The fuel pressure regulator (on the fuel rail) is a common issue.

Use only Bosch or Volvo brand.

nzxtnzxt · Post by **nzxtnzxt** » 23 Aug 2025, 11:43

The fuel pressure sensor is 100% functional; the problem lies in the valve in the pump – see photo 1.

Post by **cn90** » 23 Aug 2025, 17:26

In the US, a new Bosch fuel pump is only $120-$150 (one can find it on eBay)...

Post by **jimmy57** » 23 Aug 2025, 19:18

The valve pictured is the max pressure relief. The other item holding pressure is the check vale integrated into fuel pump. When you hook up the fuel line to sender top you have both in the circuit. Did you remove the sender and actually see it dripping? The fuel sender assembly fixes both leak sources regardless.

Vova585 · Post by **Vova585** » 23 Aug 2025, 21:17

I agree with jimmy57.
However, if the money are really tight one can always buy just fuel pump made by Bosch or pierhburg and integrate it into the original sending unit. Another alternative is to source a one way check valve from aliexpress or any other more trusted European websites. Can either integrate it inside of the tank(the closer to the pump-the better) or prior to fuel filter. I am not recommending this option, but I was less fortunate in life before, to look and implement "Jakoś to będzie" aproach

nzxtnzxt · Post by **nzxtnzxt** » 24 Aug 2025, 03:26

jimmy57 wrote: ↑23 Aug 2025, 19:18 The valve pictured is the max pressure relief. The other item holding pressure is the check vale integrated into fuel pump. When you hook up the fuel line to sender top you have both in the circuit. Did you remove the sender and actually see it dripping? The fuel sender assembly fixes both leak sources regardless.

The problem is the valve in photo 1. The valve in the pump is working, as is the pump itself, but pressure is escaping through the integrated valve in the pump basket.

nzxtnzxt · Post by **nzxtnzxt** » 24 Aug 2025, 03:32

Vova585 wrote: ↑23 Aug 2025, 21:17 I agree with jimmy57.
However, if the money are really tight one can always buy just fuel pump made by Bosch or pierhburg and integrate it into the original sending unit. Another alternative is to source a one way check valve from aliexpress or any other more trusted European websites. Can either integrate it inside of the tank(the closer to the pump-the better) or prior to fuel filter. I am not recommending this option, but I was less fortunate in life before, to look and implement "Jakoś to będzie" aproach

For future reference, do you have the number for the Bosch,Pierburg pump? because the original one with the number 0580454022 is not available on the market and I do not have the parameters for this pump. The check valve will not solve this problem 100%, it will only solve the pressure drop from the rail, but it will not solve the problem of the controller reaching the set pressure of 520 kPa, because the valve in the pump basket allows gasoline to pass into the tank.