Domzs Posted February 16, 2013 Share Posted February 16, 2013 I have a question about brake booster . My car is a 78 which came with standard trans . Now has 02 LS1 with auto trans . Noticed the brakes kinda weak to hold the car at idle , really have to press hard on pedal to keep it from creeping and it idles only at 600 rpm . Brake sys. is stock with 8 in booster . Thinking about installing a 10 in booster . Question is has anyone done this and how much improvement will it give ? Thanks . Quote Link to comment Share on other sites More sharing options...
Dans toy Posted February 16, 2013 Share Posted February 16, 2013 I went to the 10" booster / toyota 4 piston up front and it made a big difference. You may have a brake issue if you can't easily hold your car at a dead stop. Quote Link to comment Share on other sites More sharing options...
Domzs Posted February 16, 2013 Author Share Posted February 16, 2013 Brake sys is good . Worked fine with standard trans , no load like auto trans . Bought the car a year ago and it was sitting in the gargage for 5 + yrs . I already replaced wheel cylinders , master cylinder , and flush the whole sys when i got it . It takes more effort to hold the car still . Just wondered if anyone upgraded to 10 booster and saw a big different . This car definitely needs big brakes upgrade . Quote Link to comment Share on other sites More sharing options...
mattd428 Posted February 17, 2013 Share Posted February 17, 2013 Is your tcc solenoid hooker up? If its not it will push the car forward. The computer wants power when your not on the brakes and should lose power when on the brakes. Quote Link to comment Share on other sites More sharing options...
rags Posted February 17, 2013 Share Posted February 17, 2013 Is the vacuum check valve on the vacuum hose to the booster? Connected in the correct direction? Joe Quote Link to comment Share on other sites More sharing options...
Domzs Posted February 17, 2013 Author Share Posted February 17, 2013 Is your tcc solenoid hooker up? If its not it will push the car forward. The computer wants power when your not on the brakes and should lose power when on the brakes. I haven't done it yet , having too much fun driving the car . LOL . Without brake switch hooked up i just don't have lock-up operation . That's why i haven't taken it on the hiway . Quote Link to comment Share on other sites More sharing options...
Domzs Posted February 17, 2013 Author Share Posted February 17, 2013 Is the vacuum check valve on the vacuum hose to the booster? Connected in the correct direction? Joe I'm using the Z check valve . It has good braking just the way it was before . Since it now has an auto trans , seems like more effort on the pedal to keep it from creeping at the stop . I don't know if auto Zs came with 10 in boosters and standard with 8 in . With 10 in booster , pedal effort would be less , my thinking . Quote Link to comment Share on other sites More sharing options...
PLATA Posted February 17, 2013 Share Posted February 17, 2013 (edited) I had a similar problem with my 72 with an LS1, disk on all corners, it did what your is doing, put a rebuilt Datsun booster and no more brake issues, the old booster had a tiny leak and the LS1 brain was not happy , I am not an expert but this solve my problem FWIW Edited February 17, 2013 by PLATA Quote Link to comment Share on other sites More sharing options...
Domzs Posted February 17, 2013 Author Share Posted February 17, 2013 I had a similar problem with my 72 with an LS1, disk on all corners, it did what your is doing, put a rebuilt Datsun booster and no more brake issues, the buster had a tiny leak and the LS1 brain was not happy What size booster are you using ? Quote Link to comment Share on other sites More sharing options...
PLATA Posted February 17, 2013 Share Posted February 17, 2013 My 72 Z is an early model so it has the standard 71 booster, I found that out during my brake episode, hope this help. Quote Link to comment Share on other sites More sharing options...
Domzs Posted February 17, 2013 Author Share Posted February 17, 2013 I might go ahead and try the 10 in booster to see if it works better , only $100 . LOL . Might upgrade front brakes to Z32 calipers later , which i have from my 91 300ZX . And put something better on the ZX . Thanks . Quote Link to comment Share on other sites More sharing options...
Mikey303LSZ Posted March 14, 2013 Share Posted March 14, 2013 (edited) Domzs - Did you try the 10" booster yet? What year and model vehicle 10" booster did you buy or were you considering? The brakes on my '73 are completely stock and original (40 years old) and everything is pretty worn out. Instead of replacing with factory 240 replacements I was going to move forward with the Silver Mine Motors stage 4 front brake kit, Wilwood 1" MC, and perhaps a larger booster (stock unit is 8"). I'm looking for input on a 10" booster unit (just like you in your original post). Any advice would be appreciated. Thanks - Mike Edited March 14, 2013 by Mikey303LSZ Quote Link to comment Share on other sites More sharing options...
Domzs Posted March 14, 2013 Author Share Posted March 14, 2013 Domzs - Did you try the 10" booster yet? What year and model vehicle 10" booster did you buy or were you considering? The brakes on my '73 are completely stock and original (40 years old) and everything is pretty worn out. Instead of replacing with factory 240 replacements I was going to move forward with the Silver Mine Motors stage 4 front brake kit, Wilwood 1" MC, and perhaps a larger booster (stock unit is 8"). I'm looking for input on a 10" booster unit (just like you in your original post). Any advice would be appreciated. Thanks - Mike Not yet , too much work to do . Trying to get all 3 today , 8 , 10 and 87 300zx ( which i have ) and see . Quote Link to comment Share on other sites More sharing options...
Domzs Posted March 16, 2013 Author Share Posted March 16, 2013 (edited) The 87 300ZX won't work without mod. and it's about 8" diam. but a little thicker . Going to use the 10" booster with bigger master cylinder , 79-81 280ZX . Unless i can find a different master . Here are 2 pics. 10" booster will not work with standard trans w clutch master cylinder . This is the reason why standard trans. has 8" booster . Edited March 16, 2013 by Domzs Quote Link to comment Share on other sites More sharing options...
Zfan1 Posted March 17, 2013 Share Posted March 17, 2013 I did the swap to discs, 300zx rotors on all four corners and 240sx rear and toyota 4 runners calipers up front. I also swapped to the 280Z master with newish booster. My brakes suck, the back are weak and the front just lock up. Anyone else have that problem? My drums and stocker fronts were way better than this combo! Quote Link to comment Share on other sites More sharing options...
Domzs Posted March 17, 2013 Author Share Posted March 17, 2013 I did the swap to discs, 300zx rotors on all four corners and 240sx rear and toyota 4 runners calipers up front. I also swapped to the 280Z master with newish booster. My brakes suck, the back are weak and the front just lock up. Anyone else have that problem? My drums and stocker fronts were way better than this combo! There are threads in here stated that you will need some kind of proportioning valve with your brake combo setup . Sounds like you are getting too much front bias . Quote Link to comment Share on other sites More sharing options...
Mikey303LSZ Posted March 17, 2013 Share Posted March 17, 2013 I went to Advanced Auto Parts today and pulled the trigger on a 280z 10" booster. Special order - should arrive on 3/20/13... Quote Link to comment Share on other sites More sharing options...
Domzs Posted March 17, 2013 Author Share Posted March 17, 2013 I went to Advanced Auto Parts today and pulled the trigger on a 280z 10" booster. Special order - should arrive on 3/20/13... How much ? Got mine at O'Reilly for $110 , lifetime warranty . Which master cylinder are using ? Quote Link to comment Share on other sites More sharing options...
Mikey303LSZ Posted March 17, 2013 Share Posted March 17, 2013 It was ~$130ish with a lifetime warranty (the receipt is in my truck as a reminder to pick it up in a few days so I don't have the exact figure). I asked for a replacement booster from a 1976 280z (my car is a '73 240). The options were an 8" (or maybe 8.5"?) and the 10". I ordered the 10". I suspect I will have to re-drill the firewall mounting holes. My dash is out so it makes that task easier. I have a 4L60E trans so I don't have to worry about clutch MC interference. Today I'm going to place an order with Silver Mine Motors for the front brake kit. I figure I'll go with the 1" Wilwood MC and a prop. valve for fine bias tuning. I was thinking of pulling the trigger on the Silver Mine Motors rear disk kit too but need to get my coil overs, struts, camber plates ordered so I think I'll sink the $ into the suspension for now. I can always do rear brakes later. Quote Link to comment Share on other sites More sharing options...
Domzs Posted March 17, 2013 Author Share Posted March 17, 2013 It was ~$130ish with a lifetime warranty (the receipt is in my truck as a reminder to pick it up in a few days so I don't have the exact figure). I asked for a replacement booster from a 1976 280z (my car is a '73 240). The options were an 8" (or maybe 8.5"?) and the 10". I ordered the 10". I suspect I will have to re-drill the firewall mounting holes. My dash is out so it makes that task easier. I have a 4L60E trans so I don't have to worry about clutch MC interference. Today I'm going to place an order with Silver Mine Motors for the front brake kit. I figure I'll go with the 1" Wilwood MC and a prop. valve for fine bias tuning. I was thinking of pulling the trigger on the Silver Mine Motors rear disk kit too but need to get my coil overs, struts, camber plates ordered so I think I'll sink the $ into the suspension for now. I can always do rear brakes later. Don't think you have to drill anything , should be a direct bolt-on . If you don't mind , test the brakes before and after changing the front set-up and let me know . I'm trying to do all my conversions with parts from local stores , not too crazy about custom parts . This makes it easier and faster to replace them ( most are lifetime war. LOL ) . Quote Link to comment Share on other sites More sharing options...
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