Anybody loose boost when climbing?

When I do steep climbs I loose l
My hydrobosst for a sec. It takes two or three pumps and it comes back. But it is odd since I don't loose my steering. So I wouldn't think it would be a fluid flow issue? What ideas could it be. It's a new issue this season. And the only changes is going to a. Sealed system with 6 psi cap. But being it only happens on slower steep climbs I can't see why that could be it

Hydroboost systems are very sensitive about the return from the booster. I had issues after running my orbital and booster returns together. I separated them and issues stopped.
Both of my hydroboost rigs run a vented resi and 3 sides and down vent hose. Stock pumps, bigger reservoirs, tube and fin coolers, stock Superduty boosters.

You think it could be somehow associated with the return pressure from having it sealed now? Would it make sense to only do it on a periodic climb? I run the PSC reservoir so it does have a dedicated return line.

I would try a vented cap and see. It's easy.

I'll give it a shot.

So i put in a new psc reservoir closer to the pump mainly because the old unit had started leaking a bit and changed it back to a cap vented system, psc standard setup and took it out wheeling this weekend and brakes sucked. I never loose my power steering but I loose my boost in my hydro boost. The treads I find on failing hydroboost all seem to be loosing both steering and brakes but thats not my issue.

I know there is some sort of accumulator that stores some level of boost its like that is not keeping fluid in it on those climbs which is odd, I know its not a pump issue, but cant seem to find data on trouble shooting or repairing these units.

Which gets pump flow first booster or orbital?

The booster gets fluid first.

I just had a thought that maybe its not actually the boost itself, Maybe its a failing MC or other MC issue, The only reason I say that is during these climbs I have zero pedal resistance it just drops to the floor for a 3-5 pumps.

I guess I assumed it was hydraulic loss of pressure but then now Im thinking of it shouldnt the pedal be really hard to push If I were loosing boost?

Yes

So maybe bleed the brakes out? and fill with fresh fluid and see if that helps and if not swap out mc? it seems odd to me it only does it during climbs..

Another thought I will have to check when I get home but a loose rotor or hub, I doubt thats the issue but I can check. The main reason is it only does it on steep climbs and never on a flat even with whoops and sharp back and forth turns.

Your brake fluid level is good and high ?

Not trying to be a smartass but I've seen sometimes the fluid going lower than the rear brakes piston and thus sending a lot of air in the system making the brakes terrible at every big incline GOING UPHILL.

We ruled the master cylinder out when we made sure it had full brakes going DOWNHILL.

That is a great question. Its is "full" I used to have it filled to the brim but with pad wear its closer to "full" line, and with the port being so far to the front maybe on those steep inclines its just enough to let an air bubble. When i get maybe ill just cap it off and try it next weekend and see if that prevents it.

That is good to know thought cause my brakes are awesome all the rest of the time, I was hoping there may be a simpler solution than swapping parts out. Ill give it a shot and report back

Double checked the fluid level. I don't think there is anyway it's getting dry on climbs. It's well above the full line and almost at the max line? Ideas??

Ok so i jacked the rig up thinging if it had loose bearings there may be a wobble when I get climbs that would be opening up the piston causing it to go to the floor till you pump it back in. I had a loose king pin but since that affects both the caliper and rotor I didnt figure that could be it?

I hate to throw parts at it by just swapping out the MC but im running low on options?

Is there a definitive way to test it?