Booster Bad?

[atkinson40]

I noticed when I stepped on the brake, the idle goes down.  I think this means the booster is somehow letting air into the intake manifold where it hooks up?

[datzenmike]

Yes, I agree... I suppose it could be the brake lights drawing down the alternator. Pull the plug out of the back of the alternator and try again.

 

The booster should be able to hold a vacuum. Shut off engine and wait 30 seconds. Listen under the dash by the pedals and depress the brake. You should hear a soft hiss sound as vacuum is released. If no sound the vacuum leaked away

 

Just for fun pump the brakes to exhaust any residual vacuum. Step on and hold the brake down. Start the engine. What should happen is the pedal should drop slightly as intake vacuum quickly builds.

[atkinson40]

On 8/17/2024 at 5:04 PM, datzenmike said:

Yes, I agree... I suppose it could be the brake lights drawing down the alternator. Pull the plug out of the back of the alternator and try again.

 

The booster should be able to hold a vacuum. Shut off engine and wait 30 seconds. Listen under the dash by the pedals and depress the brake. You should hear a soft hiss sound as vacuum is released. If no sound the vacuum leaked away

 

Just for fun pump the brakes to exhaust any residual vacuum. Step on and hold the brake down. Start the engine. What should happen is the pedal should drop slightly as intake vacuum quickly builds.

 

Failed the last two tests.   Quick online search shows a dearth of replacements for this.  Has another car replacement part been found? 

 

What are my options here?   I replaced this with a rebuilt not that many miles ago.  Can I rebuild it myself?  Or is there a source I'm not finding?

 

I think I may have seen some, but $400 for a rebuild? 

 

Seems an easier solution would be to replace the booster/master with something from a newer vehicle that is easily sourced at a much lower price?

[Stoffregen Motorsports]

47 minutes ago, atkinson40 said:

What are my options here? 

Power Brakes Sales in Sacramento can rebuild it for about $150.

[atkinson40]

1 hour ago, Stoffregen Motorsports said:

Power Brakes Sales in Sacramento can rebuild it for about $150.

 

Thanks SM,   I found a place in SD for $225.   The shipping would probably make up part of the Sacramento difference.  

 

The guy here told me two things:

 

1.  If I pinch off the line going to the intake and it stops affecting the idle when I step on the brake, it is probably the booster.

 

2.  The check valve should be one way going to the intake.

 

 

 

 

 

 

[datzenmike]

Yes, even a better idea. Pretty hard to pinch but you can pull off the intake and seal that fitting. Gotta be the booster.

[atkinson40]

18 hours ago, datzenmike said:

Yes, even a better idea. Pretty hard to pinch but you can pull off the intake and seal that fitting. Gotta be the booster.

 

Thanks DM, 

 

Before I read your post, I was able to bend the hose over in half to pinch it off.   Sure enough,  hitting the brake stops changing the idle when the hose is pinched off.

 

I see 4 bolts at the base and 4 bolts at the master that need removing.   Maybe I'll just leave the master on until I get it out.   I'm going to replace it anyway.  

 

Just need to investigate how the pedal hooks up to the booster and how to disconnect.

[datzenmike]

The booster has a rod attached with clevis and pin at the pedal end. The rod is threaded into the clevis with a lock nut and adjustable for length. 

 

If the booster is leaking vacuum it probably isn't giving full braking assist.

[Stoffregen Motorsports]

There is also an adjustment at the tip of the rod coming out of the booster into the master. This is crucial, so when you take it out, measure it and again when you get it back from the rebuilder.

[atkinson40]

On 8/20/2024 at 10:03 AM, Stoffregen Motorsports said:

There is also an adjustment at the tip of the rod coming out of the booster into the master. This is crucial, so when you take it out, measure it and again when you get it back from the rebuilder.

 

Thanks SM,  I swapped out the booster for a rebuild not that many miles ago, but a few years ago

 

I was not smart enough to do what you suggested back then so it may be off.   I can measure it and compare to when I get it back, but I think I'm going to need to measure the throw of the master and see if I can correlate it to a throw/position on the rod coming out of the booster. 

[Duncan]

On 8/20/2024 at 6:15 AM, datzenmike said:

The booster has a rod attached with clevis and pin at the pedal end. The rod is threaded into the clevis with a lock nut and adjustable for length. 

 

 

And that clevis pin is sometimes the unholy spawn of Satan to get it lined up perfectly to go through and get a cotter pin in it..  

 

 

[rosso]

Is this a fit for the B210 (and also a 510)?

 

Amazon B210 reman by cardone

 

https://www.amazon.com/Cardone-53-5300-Remanufactured-Power-Booster/dp/B000C496CC/ref=sr_1_4?crid=38QSQUYJ9JJKB&dib=eyJ2IjoiMSJ9.5T5kZxaDgULMKdZNc-TQ8dbECO0PXlqtC8dXME0xe-ugQV1A0aAn_ElJL-ZDrCu_-yr5ERtUagK27dKSbpGYrTwOx5OYmb6TL6Bosnz7jdueupUbf_aiJTRPiLFeXjzUL68-zK6mQbRg8qZdHfC0T4jEsz5A-czkZ0qfW9rAbKszkebutIXQkBxWzjEQ3pFwLtAkD_hzih9m0QwILz52Nsgr86QAw2DTsb3Qpz_qiOQ.AFybvULCOryNLtg_Pd9NVPliVQmkcygeEKQpRMI-NkE&dib_tag=se&sprefix=brake+booster+replacement+nissan+b210%2Caps%2C301

 

[datzenmike]

The 73 is 4 1/2" diameter.  The '78 is 6". I don't know what the B-210 is... Dat210guy would know. The size is limited by clutch master to the left and steering column below. The 720 got around this by having a very long pedestal.