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Discussion Starter · #1 ·
I am trying to adjust the brake booster pushrod so it is about a mm away from the piston in the brake master cylinder when inserted. However the brake booster for this car is different than most, in that the the pushrod stays inside the booster, it doesn’t extend outside of the surface like most do. You can see it in the attached photo. I called the parts support and they said you have to push down the back of the booster where it connects to the brake pedal. However this takes a ton of force, you need two hands for this. I don’t see how it’s possible to do this and hold the bolt and turn the nut to adjust the length, which takes an additional two hands. Have you guys done this job? Thanks
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There is a special service tool (09737-00020) that is effectively a wrench with a long elbow that allows you to hold the back nut while adjusting the front nut with a 7mm socket. Unfortunately, the special service tool is pretty expensive if you only plan on using it once but maybe there is someone in your area who will rent it to you.
 

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I had A Automotive Instructor. I brought In the car to pop new Pads and Rotors. This was A few years ago like 1995. He got In the car and checked the medel. He accused Me Of Adjusting the Push rod behind the Master Cylinder. He was MAD! I informed him that Was the way I bought it.. It had Me puzzled, To say the least. Any way multiple brake job's since and I haven't had to adjust A break rod. It can cause your brakes to drag if it's been put out of spec I guess so I haven't adjusted.A brake rod to this day.
 

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Discussion Starter · #4 ·
There is a special service tool (09737-00020) that is effectively a wrench with a long elbow that allows you to hold the back nut while adjusting the front nut with a 7mm socket. Unfortunately, the special service tool is pretty expensive if you only plan on using it once but maybe there is someone in your area who will rent it to you.
That tool costs as much as the brake booster itself LOL. Man I hate this design, I thought Toyota’s were supposed to be easier to work on, that’s why I switched from Nissan. I also don’t know what tool I can stick in the booster to measure the depth
 

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Did you pull a 20 in/Hg vacuum on the booster to help flatten the pancake? Try that first and take another measure.

I never had to adjust the pushrod with both OE and aftermarket master cylinders. However I ALWAYS check the pushrod to MC piston seat distance when replacing MCs.

You also shouldn't have to adjust anything on the pedal side. However, hold down the pedal with some lumber as in this video. Hold the serrated shaft while you turn the tip. See this video if your booster is of the same design:

 

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Discussion Starter · #7 ·
Did you pull a 20 in/Hg vacuum on the booster to help flatten the pancake? Try that first and take another measure.

I never had to adjust the pushrod with both OE and aftermarket master cylinders. However I ALWAYS check the pushrod to MC piston seat distance when replacing MCs.

You also shouldn't have to adjust anything on the pedal side. However, hold down the pedal with some lumber as in this video. Hold the serrated shaft while you turn the tip. See this video if your booster is of the same design:

What do you mean by pulling a vacuum on the booster?
And how are you supposed to check the distance between the piston master and the pushrod in the booster? That point is hidden inside the master. I was planning on extending it until they hit, and then turn back the other way until they almost meet.
And I’m fine on the pedal side
 

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The booster has a vacuum hose that connects to the intake manifold. This provide the power boost. The brake booster is like a balloon. When you pull vacuum on it, it actually flattens ("pancakes") a little.

Use a Mityvac from a parts store loaner program. You may need adapters to hook up to the booster.

The video shows how that person does it. I just use a straight edge and a dial caliper, then do some arithmetic. To reach 0" clearance (or no more than 0.02").
 

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Discussion Starter · #10 ·
The booster has a vacuum hose that connects to the intake manifold. This provide the power boost. The brake booster is like a balloon. When you pull vacuum on it, it actually flattens ("pancakes") a little.

Use a Mityvac from a parts store loaner program. You may need adapters to hook up to the booster.

The video shows how that person does it. I just use a straight edge and a dial caliper, then do some arithmetic. To reach 0" clearance (or no more than 0.02").
I was think of getting somebody to hold it down with their two hands, and then I adjust the pushrod nut with my two hands. Extend it out until it hits the piston in the master, then turn the other way so it is about a mm gap. Do you think this is a good idea? My dial caliper won’t fit inside the booster
 

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For adjustment method I'd still point to the video. Nothing in the back (pedal side) of the booster should be adjusted unless someone messed with it.

If you're talking about a reman booster, Cardone for one claims their boosters are pre-adjusted at the factory and no extra work is needed. I would still however do some measurements to make sure the typical clearance of 0-0.002" to avoid brake dragging some have experienced.

So if you have a reman booster in hand, I can see how it's difficult to press in the pedal side rod. What I'm saying is you don't need to do that with a decent reman booster.


I have a Harbor Freight dial caliper. No problem doing measurements on the booster or master cylinder when the MC is removed, as I have done many times. BTW, you measure the push rod in the booster by placing a straight edge over the opening.

 

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Discussion Starter · #13 ·
What the specs of that part say it's been set to?
And what source did you find for the distance you want it at?
The spec it’s already set to is not provided. In the Haynes repair manual, it says to zero the gap but all the YouTube instructions say to leave a 1/16 in gap (1.5mm) because when there is hot brake fluid it will expand push the piston in the master a bit. Also 1A auto says it’s a common problem for these Corollas not to be adjusted correctly in this video
 

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Discussion Starter · #14 ·
For adjustment method I'd still point to the video. Nothing in the back (pedal side) of the booster should be adjusted unless someone messed with it.

If you're talking about a reman booster, Cardone for one claims their boosters are pre-adjusted at the factory and no extra work is needed. I would still however do some measurements to make sure the typical clearance of 0-0.002" to avoid brake dragging some have experienced.

So if you have a reman booster in hand, I can see how it's difficult to press in the pedal side rod. What I'm saying is you don't need to do that with a decent reman booster.


I have a Harbor Freight dial caliper. No problem doing measurements on the booster or master cylinder when the MC is removed, as I have done many times. BTW, you measure the push rod in the booster by placing a straight edge over the opening.

I have a Duralast remanufactured booster, not Cardone. So you measure by putting a straight edge inside the booster, than marking it, than measuring the distance between the mark and the end of the straight edge hitting the push rod?
 

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You put a straight edge over the front opening, then use a dial caliper to measure the depth of the push rod. That's after pulling 20 in/Hg to pancake the booster, and then doing some basic arithmetic to account for the thickness of the straight edge.

Then measure the depth of the seat of the master cylinder piston, accounting for the mounting flange and depth. As I said, some arithmetic involved.

Look back at the video, he just use a clip over the opening to do a very rough measurement. But you get the idea. I just do it with higher precision using a dial caliper.

The 1AAuto (1:00 into the video) says the push rod needs to be adjusted when replacing the MC (or booster of course). But IME, I never had to do that. However, as I said, I ALWAYS check the clearance just to avoid dragging problems, which can be a pain if it happens to you.
 

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Discussion Starter · #16 ·
You put a straight edge over the front opening, then use a dial caliper to measure the depth of the push rod. That's after pulling 20 in/Hg to pancake the booster, and then doing some basic arithmetic to account for the thickness of the straight edge.

Then measure the depth of the seat of the master cylinder piston, accounting for the mounting flange and depth. As I said, some arithmetic involved.

Look back at the video, he just use a clip over the opening to do a very rough measurement. But you get the idea. I just do it with higher precision using a dial caliper.

The 1AAuto (1:00 into the video) says the push rod needs to be adjusted when replacing the MC (or booster of course). But IME, I never had to do that. However, as I said, I ALWAYS check the clearance just to avoid dragging problems, which can be a pain if it happens to you.
Thanks, I just measured it and there’s about a 0.5mm clearance, with the gasket. Is that too little, how much clearance do you usually get? The Haynes repair manual says it must beat zero, but doesn’t say a number.
 

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What does the Toyota factory service manual says. Sometime Haynes says thing that are not right. The one time I thought it was the booster rod it was something else. You want enough clearance so the booster isn't engaged all the time allowning for expansion and contraction from temperature. Like driving with your foot resting on the pedal. There should be enough Too long, brake drags with engine running, too short long pedal play. It's probably fine the way it is.
 

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Discussion Starter · #18 ·
What does the Toyota factory service manual says. Sometime Haynes says thing that are not right. The one time I thought it was the booster rod it was something else. You want enough clearance so the booster isn't engaged all the time allowning for expansion and contraction from temperature. Like driving with your foot resting on the pedal. There should be enough Too long, brake drags with engine running, too short long pedal play. It's probably fine the way it is.
I don’t have the service factory manual, is there anyway to get it for free? I installed the master and booster without adjustment and will see how it goes tomorrow. You can’t adjust the pushrod anyways, at least on this Duralast remanufactured booster from autozone. I will give an update soon on if they brake correctly.
 
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