With the kind help of flash 32 i have successfully changed my accumulator. Following set of instructions if you want to have a go. 1. put gearbox in neutral Remove F1 fuse or relay to stop pump from cutting in Remove rear right hand wheel liner- makes access a lot easier Looking at the valve block under the wing, look for a long hex nut at the top- it is 8 mm socket size with a screwdriver slot. This is a vent valve that releases pressure back to the tank. Check top is on F1 tank and vent pipe is connected as you do not want to spray fluid in the engine bay With the fuse removed overnight the pressure should have dropped to zero, crack open the 8 mm hex nut say 1/2 turn to drop off any pressure left in system. If any pressure left this will put weight on the accumulator threads and it will not move. with pressure at zero remove accumulator using strap or similar- normal right hand thread. We used a US pro self adjusting filter wrench as nothing else would grip it. Item 3097 put accumulator in vice and using say a 2 mm TIG rod, drop this into the oil hole- i used a syringe and dribbled the F1 fluid down the tig rod into the accumulator. It takes very little but it ensures no air present. With the accumulator removed it leaves a threaded opening at the top of the valve block, so using the syringe top this up to the top with fluid. refit the accumulator replace the fuse or relay and switch on key, DO NOT START ENGINE. System will pressurize- when pump stops crack open 8 mm hex vent valve for part of a second- you will hear the fluid passing through the vent valve, then close valve. This will vent any air back to the tank Do this a few times and pump will cut in and out it does no harm to do a few vents provided you maintain a level in the tank to stop air entering system. select 1st and reverse and you should be good to go clear any codes you may have.
Mike Glad it worked out and thank you for cleaning up my instructions and posting them here Dominick Sent from my moto g power using Tapatalk
The one thing learnt is that if you think you have air in the system, you can get to the vent valve on the block from the engine side and crack it open to see if it helps.
But you do need to put key in position 2 so pump pressurizes at full 40 psi , right ? So then potential air pockets are pushed out of the system? Thanks
It runs about 50 bar ( about 750 psi) not 40. Following the method everything is full of fluid and i dont see how you could get air into it.
All One of the most important part of the instructions is using the bleed /bypass valve on the power unit before engaging any gears or clutch .. (that and using the syringe to top neck of power unit You will hear the air sound when you release the pressure Before starting removal make sure in neutral and don't touch paddles or start car until you do the bleed /bypass process I added this to the instructions and is key and proven by at least 10 people this year only ..not one had air enter system .. Sent from my moto g power using Tapatalk
50 bar is too high!! 43 ideal..45 acceptable. You can adjust pressure on the power unit via the needle valve. It's is located on the power unit just about beside the pressure release screw for the accumulator..
quick question: with the engine off, and key in position 2, how many times do you shift gears (N-R-N-1, etc) before the pump primes again? Mine starts every 3 or 4 shifts... Is that normal? I have no problems otherwise, I did flush some of the fluid by the top up method like @flash32 advised...
Perfectly normal How many seconds did the pump run after If you want do that flush a few times with miles between Sent from my moto g power using Tapatalk
3 seconds or so.. So I sucked the fluid out as much as could, and replenished, and went for a 20 min drive... came back 2 days later, sucked out and topped up... Should I drive it more between the process? Thanks!
If less than 3.5 4 seconds (use a stopwatch) then i would consider changing accumulator Sent from my moto g power using Tapatalk
Not so much the mins but how many shifts (different gears) and making some good tight turns ..but 20 mins you probably did that Also if you pull relay ..the pressure will release over night and you can get more out..unless you left the hatch open overnight and never open doors etc before pulling fluid Sent from my moto g power using Tapatalk
Thanks, so if the accumulator needs changing it runs less ? I thought it would need more time to prime to the needed pressure... I will time it next time.
The most common is a collapsed diaphragm ..which removes reserve pressure..thus cycles the pump more with less time Sent from my moto g power using Tapatalk
The TCU is what solely controls system pressure. Eg it decides when the pump runs and doesn’t run. The needle valve is the pressure relief. It’s a safety meant to prevent the system from ever over pressurizing. I believe it’s set at 80 bar from the factory. I wouldn’t touch this. Sent from my iPhone using Tapatalk
Went back to the car, and changed the remaining 2 relays for the fans (in the trunk, where the light is, doh). Pretty messy white **** coming out of the rubber seals, not sure what is that, dried talk??? Anyway, back to F1 system: with system pressurized, contact on, engine off, I cycle through exactly 4 gears before the pump comes on. Everytime... And everytime it comes on for less than 3 seconds. Hard to quantify to the milisecond, but it's something around 2.8 seconds. My pump does not run too long once I open the door, under 10 seconds. Once I put the contact key on position 2, it also runs for under 4 seconds to pressurize. Do you think I have an accumulator problem; on the way out ?? I also followed the manual to fill the F1 fluid, and surely made a mess once the pressure went off overnight, it all came out of the overfill pipe. Lesson learned. Many thanks.
Actually the timing and the fact that you made a mess if you followed the proper procedure both point to a weak accumulator How many years / miles ? Did you fully pressurized the system before measuring and have about 1/4 in of fluid above disk ? Sent from my moto g power using Tapatalk
2005, 18k miles. I did pressurize it , key in position 2, checked and topped up after pump stopped... I actually topped up to much, I followed the little white gauge which is on the lid, and I topped up until it was almost to the "max" as per this: Image Unavailable, Please Login which I now understand it is not the proper process anymore, I think I overfilled... In your measurements, that corresponds to almost an inch on top of the disk...
Correct not good Just turn key on ..when pump stops immediately measure it ..half a thumb nail...25 in.. 5 or 6 mm ..pick whick one Sent from my moto g power using Tapatalk
Also a good way ..you be surprised how many cars come from mechanic and overflow over night Sent from my moto g power using Tapatalk
I would like to try to rebuild a 430 Accumulator. Does anyone have a confirmed bad one they can send me? I will pay shipping.
