Booster Pump / Accumulator Noise diagnosis

[2001LC]

Still having issues. I just rebuilt the master cylinder. Brakes work fine. If I bleed the system, it’s perfect for a few days. Then the noise and alarm return. I believe a possibility is the o’ring, spring, and silencer tube between the pump and accumulator.

I’m calling my local dealership to see if they stock them seperate.

I'm really interested to see if that works.

I just did repaired a bad brake issue near point of failure, and was going to do job piece by piece, with rebuild and used parts. To see what would solve issues and try to save some coin. But owner just wanted new.

This one had varying times in test (IG switch off and pump pedal than time run time of motor). Colder the longer the run times in test. The less used the long the time. Pedal pressure would drop off new 40 pumps. In new low mile or new booster assembly 25 times until pedal falls off.

This one also had bubbling in reservoir while screeching at times. Again more so when cold.

 

[MissouriLC]

I'm really interested to see if that works.

I just did repaired a bad brake issue near point of failure, and was going to do job piece by piece, with rebuild and used parts. To see what would solve issues and try to save some coin. But owner just wanted new.

This one had varying times in test (IG switch off and pump pedal than time run time of motor). Colder the longer the run times in test. The less used the long the time. Pedal pressure would drop off new 40 pumps. In new low mile or new booster assembly 25 times until pedal falls off.

This one also had bubbling in reservoir while screeching at times. Again more so when cold.

If the reservoir is bubbling and during the screeching, this would seem to suggest a faulty pressure release valve. As detailed in my booster motor rebuild thread, I needed to run my pump motor jumpered directly from the battery for about 80 to 90 seconds before the reservoir started bubbling. That suggests to me that reservoir bubbling is something that should never happen under normal circumstances.

I wonder if the cold also affects (i.e. reduces) the resistance of the pressure release valve, causing the variable run time, bubbling, and screeching?

 

[2001LC]

If the reservoir is bubbling and during the screeching, this would seem to suggest a faulty pressure release valve. As detailed in my booster motor rebuild thread, I needed to run my pump motor jumpered directly from the battery for about 80 to 90 seconds before the reservoir started bubbling. That suggests to me that reservoir bubbling is something that should never happen under normal circumstances.

I wonder if the cold also affects (i.e. reduces) the resistance of the pressure release valve, causing the variable run time, bubbling, and screeching?

It's why I'm so interested in seeing @bdruff replace the "o’ring, spring, and silencer tube". But someone did this in mud recently, on my suggestion. It did not stop the bubbling and screeching. We don't know if he did a good job. It's also not to say, that o’ring, spring, and silencer tube can't be one reason for this and accumulator another.

I've got a booster assembly on my bench now, that was intermittently bubbling and screeching. I'll be tearing down. But I'll not likely be able to learn anything helpful outside of motor. I asked the above reference re builder about testing. He said just that. Out side of vehicle there aren't any test for pump, o’ring, spring, and silencer tub or accumulator..

 

[bdruff]

It’s ordered. Less than $20 from the dealership for the oring, spring, and rod. I have a booster and accumulator unit on my bench. I was able to remove the accumulator by gently using a pipe wrench. I’m going to try and replace the 3 pieces without removing the whole unit... again.

 

[hickuptruck]

This is exactly me right now this weekend. Replaced the booster motor last year. This week it got below freezing and my screeching noises came back along with all the error buzzing codes. Ordered an accumulator + oring+ valve. Will be using a Toyota 4wd hub tool to unscrew accumulator off.

 

[2001LC]

This is exactly me right now this weekend. Replaced the booster motor last year. This week it got below freezing and my screeching noises came back along with all the error buzzing codes. Ordered an accumulator + oring+ valve. Will be using a Toyota 4wd hub tool to unscrew accumulator off.

Did you replace booster motor, because it would not run?

 

[bdruff]

47950-60010

This part number brings up the accumulator. Is the pump a separate part? My order for the o'ring, spring, and rod are on backorder.

 

[bdruff]

 

[bdruff]

I spoke with the dealership and they said the pump and motor are sold as a unit. The pump is easily removed from the accumulator and motor. 2 Allen bolts for the motor and the accumulator just screwes right off. I'm wondering if I can source the pump from other vehicles like a previous post suggested a 4-runner. There are a few salvage yards but I've never seen a land cruiser or lx470 anywhere.

 

[bdruff]

I ordered a booster one time and the accumulator was smaller. I found it was from a Lexus gs300. I think the pump may be the same. Im here at the junkyard and they have one. Anyone know of it is the same?

 

[bdruff]

I bought it. I'm pretty sure it's the pump itself that is bad. I still have the new spring, rod, and o'ring at home. I'll build a unit and get it installed this week.

 

[bdruff]

I'm not 100% but it looks like it's a possibility.

Should I try it or sell this one on eBay and keep looking? The o'ring is not reusable so I'm on the fence about trying it. If it did work, it would open a lot of possibilities for folks.

The main difference is the port where the hard brake line that connects to the master cylinder.

There are also subtle differences in the shape but everything else lines up.

 

[bdruff]

The motor and accumulator are definitely smaller but I'm only interested in the pump itself.

 

[bdruff]

I put it on eBay. I just don't want to risk it.

 

[Landcruiser949]

After reading the replies since I've posted, the oring, spring, and silencer tube have grabbed my attention. I bought my accumulator brand new from Toyota. It should come new with the silencer, spring, and oring as well correct?

 

[bdruff]

After reading the replies since I've posted, the oring, spring, and silencer tube have grabbed my attention. I bought my accumulator brand new from Toyota. It should come new with the silencer, spring, and oring as well correct?

I think the spring, push rod, and o'ring were separate parts. They were around $20 for all 3 but had to be ordered from my local Toyota shop.

 

[Landcruiser949]

I think the spring, push rod, and o'ring were separate parts. They were around $20 for all 3 but had to be ordered from my local Toyota shop.

But will they fix the problem?

 

[bdruff]

But will they fix the problem?

I don't know, but I doubt it. I think the problem is in the actual pump under the accumulator.

 

[hickuptruck]

I've got a new motor rebuild, new accumulator + oring, spring, and tube. It still gave me error codes, so no its not 100% that it will be fixed.

 

[bdruff]

I've got a new motor rebuild, new accumulator + oring, spring, and tube. It still gave me error codes, so no its not 100% that it will be fixed.

Again leading me to believe that it's the pump itself under the accumulator.