New accumulator bad?

lanteau

Registered User
I just got my AC Delco accumulator I bought on Amazon today. I just got done putting it in the car and priming it. I could only get 2 brake presses on my old stock accumulator before the pump would kick on. Naturally I decided to perform this same pedal test on the new accumulator. I can only get 4 pedal presses on the new one :eek:

I realize that the AC Delco part seems to have a smaller capacity than the factory ford one. But it shouldnt be that much of a difference. Is this something that has to break in (no pun intended) to be able to hold its full capacity? I realize its a diaphragm inside there and was thinking its something that needs to be stretched out over some use to make it work to its full potential?

It definitely is new old stock. So do you think it's just bad and I should return it? Or is 4 pedal presses acceptable? Thanks
 
I think that 4 pumps is acceptable...

I just got my AC Delco accumulator I bought on Amazon today. I just got done putting it in the car and priming it. I could only get 2 brake presses on my old stock accumulator before the pump would kick on. Naturally I decided to perform this same pedal test on the new accumulator. I can only get 4 pedal presses on the new one :eek:

I realize that the AC Delco part seems to have a smaller capacity than the factory ford one. But it shouldnt be that much of a difference. Is this something that has to break in (no pun intended) to be able to hold its full capacity? I realize its a diaphragm inside there and was thinking its something that needs to be stretched out over some use to make it work to its full potential?

It definitely is new old stock. So do you think it's just bad and I should return it? Or is 4 pedal presses acceptable? Thanks

IMHO, I think 4 pumps, up from two, especially with the smaller capacity accumulator is acceptable. Mine gets about that. Of course, I still have the brake pulling problem, but will hopefully be taking care of that this weekend. Am replacing both front rubber brake lines.

Did you not say that yours pulls as well? Has that changed any with your new accumulator? How much was the accumulator?

You might want to also do a thorough brake bleed on all wheels.
 
4 is OK. You have a good one. As a follow up test though, you should test the ABS on a wet surface some time. If an accumulator is bad, your ABS won't work properly.
 
I still have the brake pulling problem, but will hopefully be taking care of that this weekend. Am replacing both front rubber brake lines.

You might want to also do a thorough brake bleed on all wheels.
As part of my trouble shooting my brake pull problem, I bled the main unit by running the output lines back into the reservoir with fittings and clear plastic tubing and then pumping the brake pedal until the fluid ran thru w/o any air bubbles. :rolleyes: They sell a kit in the "Help" section of the parts stores. You might want to try that.

Oh, and don't overlook tires. Swap them around to see if they are the cause. For that matter, swap rotors, pads, etc.
 
Alright I guess I will be happy with 4 then. It does seem to hold pressure very well when sitting where my old accumulator would have to charge for 30-45 seconds after sitting 5 hours at work.

Honestly, knock on wood, but I think I fixed my brake pull issue on Sunday when I bled both front brakes after I changed my upper control arms. No air bubbles came out, but I assume it very well could have been a particle clogging one of the rubber lines, and the fluid flowing when I bled them flushed it out.

Some people would say that obviously the bad ball joints was causing the pull. But I know this is not true because when I would get the bad pull to the left, my pedal would be really hard too, so it was definitely a brake problem.

I'll let you know if it comes back, but right now it seems fine. Now I guess I just need to enjoy my working brakes.
 
The capacity of the AC Delco accumulator is .25 L and the OEM accumulator is .37 L

This means the AC Delco has about 32% smaller capacity.....

I think you will be fine, but the pump motor will have to work a little bit more.....
 
I'd like to see you measuring that. :rolleyes: Must be quite a challenge to squeeze those drops of fluid into that tiny hole at 2300psi :eek:
 
Normal pressure, just like you are coming to a stop.....

What you are trying to accomplish is to relieve pressure in the accumulator....
 
Normal pressure, just like you are coming to a stop.....

What you are trying to accomplish is to relieve pressure in the accumulator....

ok, because i can get two pushes to the floor or a handful of light/normal pushes before the pump comes on.
 
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