AHC pump fail

[kunu]

Can I drive after my AHC pump has failed? It is stuck in the low position and flashing “off”. Took it to the dealer and they said the the pump is “fried”.

At 125k miles, needless to say I’m sickened by the 6k cost to replace it. I guess it’s a bittersweet day though, time to throw on a lift and 33s

Am I say to drive this to a shop of my choosing? Or does this need towed

Also seems like the general consensus is 1.5-2” OME lift. Interested to hear how the daily driving experience is on that if anyone has switched to that from AHC. Although I’m aware that nothing will compare…

 

[BullElk]

At 125k miles, needless to say I’m sickened by the 6k cost to replace it. I guess it’s a bittersweet day though, time to throw on a lift and 33s

Unfortunate for sure, however.....
Another example of a low mileage hundy being far from immunity. And you can replace the AHC pump light years cheaper than $6k. You could've already had 33's on with the AHC if you wanted.

You can drive in low. Ain't fun but you can.

Although I’m aware that nothing will compare…

Correctamundo

 

[kunu]

Unfortunate for sure, however.....
Another example of a low mileage hundy being far from immunity. And you can replace the AHC pump light years cheaper than $6k. You could've already had 33's on with the AHC if you wanted.

You can drive in low. Ain't fun but you can.


Correctamundo

Thanks for your input, and yeah After looking into this more. The 6k quote to replace the pump seems ludacris and I think my service tech might’ve just been clueless…

I guess my question now is, is it worth saving the AHC? If my pump has failed, should I expect more things to domino if I fix it? I know these can become a money pit, but is this the time to ditch it

I know I can run 33s on AHC but I told myself I wouldn’t start modding until things broke…. But I guess needing new suspension came before worn tires. Which is the bittersweetness

 

[NE Snowman]

I’d recommend reading the ABCs of AHC thread. Clearly they didn’t give you a full diag, I assume not many of the techs in dealerships work on 100s anymore.

People have over 400k on AHC, and some of the fixes are not hard at all. I would attempt to troubleshoot first. If you haven’t needed to lift your truck yet, will you need to at all? There’s also a sensor lift mod for AHC if you got to that point.

Rust would be the end for most, the lines are hard to replace but we’ve had forum members do them as well because they didn’t want to loose the suspension.

Thread 'The ABCs of AHC - How to Measure, Flush, and Adjust all in one place'

May 29, 2020

I initially put this in the Definitive list of AHC maintenance items thread, but at almost 800 posts long and growing, it's going to get buried and the thread itself is very unwieldy.

In an attempt to make as focused a summary as possible, I present "The ABCs of AHC." It's intended as a comprehensive, linear checklist for anyone who needs to get their AHC back into factory tune. Information gathered from as many sources as I could find on this forum; I take no credit for developing any of this, just bringing it all together as much as possible. Special shout outs to...

• LndXrsr
• ahc
• Replies: 499
• Forum: 100-Series Cruisers

• 
• 
• 

 

[BullElk]

I guess my question now is, is it worth saving the AHC?

My first thought is absolutely it is.....if the pump is the solution. If this was a vehicle used for longish overlanding trips, that would be the only reason I would lean toward a static suspension. And I say that because I will do anything on the planet to not drive 8 hours home in L again.

 

[kunu]

My first thought is absolutely it is.....if the pump is the solution. If this was a vehicle used for longish overlanding trips, that would be the only reason I would lean toward a static suspension. And I say that because I will do anything on the planet to not drive 8 hours home in L again.

Fair enough. I see that you had a write up about replacing the AHC pump in 2020. It doesn’t seem terribly difficult. I’m not a wrencher by nature, but that seems fairly straight forward. I think I’ll give it a shot

I’m gonna chalk this up to young technicians at Toyota working on old cars. Cause I just called him and he said we can get a new pump for 1k…. The kid is lost I think

I’ll follow your thread to replacing the pump and see how that goes!

Thanks Mud

 

[NE Snowman]

I’m gonna chalk this up to young technicians at Toyota working on old cars. Cause I just called him and he said we can get a new pump for 1k…. The kid is lost I think

I would call around and see if you can find a shop that has a mechanic familiar with a 100 series. It's only time on the phone and its better than the random draw at a dealer.

Another example of a low mileage hundy being far from immunity.

Yup, they like being in motion, not parked in a garage. I've found buying someones daily is a better choice than the low mile garage queen.
You got an impressive amount of miles across your fleet.

 

[BullElk]

@kunu there are many other mudders here that are AHC experts that may can give you lots more instructions on troubleshooting the pump, motor, etc.

Yup, they like being in motion, not parked in a garage. I've found buying someones daily is a better choice than the low mile garage queen.
You got an impressive amount of miles across your fleet.

Although I did give up on trying to stay with the AHC in my '06 overlander, I do have 480k miles on the original AHC pump on one of my '00s. And I use it every day.

 

[suprarx7nut]

Can I drive after my AHC pump has failed? It is stuck in the low position and flashing “off”. Took it to the dealer and they said the the pump is “fried”.

At 125k miles, needless to say I’m sickened by the 6k cost to replace it. I guess it’s a bittersweet day though, time to throw on a lift and 33s

Am I say to drive this to a shop of my choosing? Or does this need towed

Also seems like the general consensus is 1.5-2” OME lift. Interested to hear how the daily driving experience is on that if anyone has switched to that from AHC. Although I’m aware that nothing will compare…

If you opt for removing AHC, just do standard Toyota shocks and springs. Lift it ~1" if you want, but the plain OEM suspension is pretty darn good for daily use.

The lift won't unlock 33" tires - you can do that at factory lift!

 

[2001LC]

I'm doubtful pump is fired. They do happen, but not common. Even ones, that has come to without fluid in reservoir, pump and pump motors have been fine. I've never seen one bad, only read about them. Exception is, the use of AHC fluid from plastic bottles that had jell in them.

Service manager see in low and flashing off. Read codes and calls pump bad. Call can't be made by DTC (codes) alone. Next is proper diagnostics, which can take a lot of time.

Number one I've found, other than pressure way out of spec. Short in wiring. Mostly those wires and wire blocks, found underbody.

 

[kunu]

I'm doubtful pump is fired. They do happen, but not common. Even ones, that has come to without fluid in reservoir, pump and pump motors have been fine. I've never seen one bad, only read about them. Exception is, the use of AHC fluid from plastic bottles that had jell in them.

Service manager see in low and flashing off. Read codes and calls pump bad. Call can't be made by DTC (codes) alone. Next is proper diagnostics, which can take a lot of time.

Number one I've found, other than pressure way out of spec. Short in wiring. Mostly those wires and wire blocks, found underbody.

Interesting. So the guys diagnosing it said that the pump was not responding to power. They had power going to it but it just wouldn’t do anything. Are you saying that can be fixed without replacing the pump?

 

[2001LC]

Interesting. So the guys diagnosing it said that the pump was not responding to power. They had power going to it but it just wouldn’t do anything. Are you saying that can be fixed without replacing the pump?

If they did actually jump, with 12 volt to pump motor, correctly. And pump motor did not run. Motor is bad and can be rebuild. I made a jumper cable for the purpose of testing motor.

All motor do wear out brush and or commutator. I've seen over 400K miles AHC working fine. So why would motor fail at such low miles. Two things I can think of:

• Motor running continuously or very long periods. Which they're not design to run, more than a few minutes. They're design to frequently for short duration.
• Resistance in power to motor. Result in commutator burn out. We see this in brake master booster motor all to often.

I use a new wire housing block from Toyota & pigtails and old extension cord.

BTW: If you do end up needing a motor/pump assy. List is like $4K. Alternatively get a used one. I've had 3, until two days ago. When someone needed one. Which I suspect he didn't need, until he rebuild his pump (his motor did respond). His was the 98-early 00. Which has an early pressure sensor, with flat inline wire housing block. Which he got my only one like that. He said the pressure sensors are no longer available for the type.

The late 00 -07 have a triangular wire housing block. Which I do have two complete AHC assy, pulled from working 100 series. You can also find them on ebay.

 

[kunu]

If they did actually jump, with 12 volt to pump motor, correctly. And pump motor did not run. Motor is bad and can be rebuild. I made a jumper cable for the purpose of testing motor.

All motor do wear out brush and or commutator. I've seen over 400K miles AHC working fine. So why would motor fail at such low miles. Two thinks I can think of:

• Motor running continuously or very long periods. Which they're not design to run, more than a few minutes. They're design to frequently for short duration.
• Resistance in power to motor. Result in commutator burn out. We see this in brake master booster motor all to often.

I use a new wire housing block from Toyota & pigtails and old extension cord.
View attachment 3999130

BTW: If you do end up needing a motor/pump assy. List is like $4K. Alternatively get a used one. I've had 3, until two days ago. When someone needed one. Which I suspect he didn't need, until he rebuild his pump (his motor did respond). His was the 98-early 00. Which has an early pressure sensor, with flat inline wire housing block. Which he got my only one like that. He said the pressure sensors are no longer available for the type.

The late 00 -07 have a triangular wire housing block. Which I do have two complete AHC assy, pulled from working 100 series. You can also find them on ebay.

Thanks! Mine is a 99 so looks like I’m out of luck. I’m going to go ahead and order a new one because rebuilding sounds a little outside my scope.

If you want I’d ship you the “broken” one, for you to rebuild and maybe re sell. If you’re into that, it’ll probably go in the trash at my house.

 

[2001LC]

Thanks! Mine is a 99 so looks like I’m out of luck. I’m going to go ahead and order a new one because rebuilding sounds a little outside my scope.

If you want I’d ship you the “broken” one, for you to rebuild and maybe re sell. If you’re into that, it’ll probably go in the trash at my house.

Sure, PM your email.