How to increase Power Steering pressure.

Big tires and lockers make it hard to steer. No reason to struggle though, you can increase the pressure and flow in your steering pump. The flow effects the feel of the steering and the pressure effects the power. Too much flow and the steering gets twitchy, too much pressure and you start blowing hoses or seals. Also only increasing the flow reduces the pressure.

Start by removing the black flow restrictor fitting from the pump. This can be done without removing the pump from the truck, be carful not to drop anything.


Behind the restrictor is the flow control valve and then a spring.


To increase the flow or ease of turning drill out the hole in the restrictor. Ive read not to go bigger then 5/32 but id say even this is too big for a Toyota. I like .111 or a #34 drill bit. Ive seen 2 styles of restrictors, some have 1 hole, some have 2 smaller holes. The flow can be increase for either style just be carful not to go too big.


To increase the pressure, or the amount of force you can apply to your tires, unthread the tip from the flow control valve (don't fuck up the OD of the valve body). You'll see some shims under the tip then a ball, ball seat, and spring. Removing shims from under the tip will increase the bypass pressure. Adding shims under the spring will also increase the bypass pressure. I think stock pumps are rated for 1050-1100 psi. After market high performance pumps are available in 1200,1400,1600 psi models. My pump came with a .26mm shim and a .56 mm shim under the tip. I removed both shims.


Now put it all back together, bleed, enjoy...

Disclaimer: Do this mod at your own risk. Ive been running modded pumps on 2 different rigs over a period of 8 or so years. The pumps do tend to die a little faster, but overall reliability is acceptable. I've never had a catastrophic failure, Eventually the pumps just start feeling weak when the vanes wear down.

 

Nice, never seen this done for the Tacoma pump before. I drilled out the restrictor on my 85 running 37s with hydro assist.

I've wondered about doing the same for the Tacoma because I seem to kill at least one pump a year since going to 35s even with a big 7x12" cooler installed.

 

IMO drilling out the restrictor is the less important part, the factory feel isn't bad. The important part is increasing the pressure so your pump doesn't go into bypass mode as soon as your tires on a rock.

 

I'll have to consider doing it then. I have noticed that happen more and more.

Though I told myself I was not going to wheel the Tacoma much til I can get tons under it

 

This is interesting.
Thanks for documenting this. Do you know if it's the same process between a 4 cyl and 6 cyl PS pump?
Never had to take one apart so I don't know if they are different at all internally. I would imagine not.

This also makes me wonder how much pressure the rack and pinion can handle. Would maybe benefit from bumping up the pressure just a bit. Nothing crazy, but maybe something like 200-250 would make a noticeable difference.

 

Interesting, thanks for posting. Any concern about long term effect of increasing the pressure?

 

It's pretty likely they're they're similar or the same inside. That 6 cyl restrictor looks like the same one that came inside of my 85-9x 22RE pump

 

Interesting I doubt any of your worn out pumps would ever go for core.

To many goodies can be reused.

 

Some sort of discrepancy here. I’ve taken apart several pumps off 5vz. So far they have all looked like this, just different markings.

 

Yes I think that's an oem toyota pump, I've only opened up one like that. Im usually too cheap for the oem pumps, every aftermarket pump I've opened has had the adjustable flow control valve and i have 4 of them.

Ive also recently done a pressure test on a stock vs modified pump. The results were surprising, ill have to post up video later

And ive figured out one more step to the pump mod that should help the longevity and quite down a noisy modified pump by allowing it to suck more fluid from the resi. I have pictures to post for this also

 

I noticed some times the modified steering pumps have a tendency to whine a bit louder then normal. This usually means the fluid reservoir cant supply the pump fast enough. In order to solve this issue I decided to do a couple things to allow more fluid into the pump.

First; drill out your reservoir outlet, I slowly stepped up to a 7/16 drill bit. Do this carefully because the material will be very thin at the o-ring groove and be sure not to drill through the screen in the resi (wrap some tape around the bit to prevent it from going to deep)


Second; after you have disassembled your pump take a die grinder and open up the pump inlet by girding this ridge away.



Third; Take your die grinder again and open up the hole with the red arrow without touching the hole with the yellow arrow. I didn't get a before pic of this step unfortunately.


Fourth; Deburr all rough edges, Clean the shit out of everything, and reassemble/install

 

Here is video of a modified steering pump vs a stock oem steering pump.

https://imgur.com/a/clLvTcn

I was actually surprised to see the stock pump hit 1400 psi, I was expecting somewhere between 1100-1200 psi.

1800 psi on the modified pump was more then I was shooting for. I might add one the shims back to the flow control valve to try and get the pressure somewhere around 1650.

 

That would explain it, they were all factory pumps. Any chance you wanna let go of one of those aftermarket valves?