datsunlover Posted June 14, 2004 Share Posted June 14, 2004 Well, it looks like I may be driving my car in the next month or so, so I figured it's time to sort this out. Last year when I bought my car and drive it home, I found the brakes to be.. well, not that good.. There is PLENTY of pressure at the pedel, and no leaks that I can find. Although the rear reservoir at the M/C is low.. (???) The thing is, they felt very weak.. as in, it was VERY hard to stop the car. (my test drive was.. interesting. Im glad I remembered how to heal toe downshift!) Its all stock, and the front rotors and pads were 'new' (Im sure after sitting for the last year they will need some attention..) but the rear flex lines and drums are shot. Not leaking, but cracked and old. I have the new lines and am dredding putting them on. (I HATE brake lines..grrrr) Now, I'm thinking maybe I just was used to my brakes in my truck (with vented disks, big calipers, ect) and there is nothing wrong with my Z.. but I dont like taking chances with brakes. What do you guys think, is there a problem here or what? Quote Link to comment Share on other sites More sharing options...
Synlubes Posted June 14, 2004 Share Posted June 14, 2004 When you pull the drums, look closely at the wheel cly. Carefully pull back the rubber seals on the wheel cly. If it looks moist, well . . . $ $ $ Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 14, 2004 Share Posted June 14, 2004 If your brakes are taking a lot of peddle pressure to actuate them it sounds like the vacuum booster is not functioning. I'd check the vacuum line going to it first and then the booster itself. Otherwise, if you are just mashing them and it's not working that well I'd start by thoroughly bleeding them again -if you haven't already. They can get extremely mushy and have a lot of pedal travel if they have air in them which is easy to do either from just very old fluid or driving them exceptionally hard - or the fluid getting too low in the MC. Obviously checking the cylinders for leaks is an excellent step too. Your Parking brake is the adjuster for the rear drum brakes. Cycle the handle up and down about a dozen times and see if things are better. If the adjusting mechanism is working it should improve. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted June 14, 2004 Author Share Posted June 14, 2004 Ok... thanks guys, I'll have to try that stuf.. I hope this doesnt get too expencive.. I do want to drive this car this summer! Quote Link to comment Share on other sites More sharing options...
datsunlover Posted June 24, 2004 Author Share Posted June 24, 2004 Just resurecting this post here to pose another couple of questions: I believe my vac assist is shot. (could be the line/valve looking thingy but I dono..) I was talking to a friend of mine, and he suggested taking the vac assist right out/off the car. IE; mount the master cyl right to the firewall/brake pedel, and just have completly manual brakes. So here's the Q's: Is this possible? And if so, is it advisable? I know I will be dealing with a harder pedel (more leg work.. meh) but I need to know if the system will work properly like this. Anyone heard of this or done it? Thanks. Quote Link to comment Share on other sites More sharing options...
Savage42 Posted June 24, 2004 Share Posted June 24, 2004 Yep, you just need the adapter plate like on a 510 and other cars that run that. I ran ZX brakes front & rear with a ZX master w/o a booster on my 510 with great success. So, it will work, but you'll also need the rod from the brake pedal to MC that the non boosted cars use. Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 24, 2004 Share Posted June 24, 2004 Are you absolutely positive the booster is bad? Have you verified that the vacuum line from it to the engine has no leaks? Personnally I would prefer to have the assist. It's no fun standing up in your seat trying to get stopped if a "situation" develops. My '77 has it's original booster and it still works fine so it may pay to check around for a salvage vehicle that would have a donor for you. Why invest time and effort to make your brakes harder to use? Quote Link to comment Share on other sites More sharing options...
DaleMX Posted June 24, 2004 Share Posted June 24, 2004 Brake Boosters are like 80 bucks at Autozone. Sounds Cheap to me. Quote Link to comment Share on other sites More sharing options...
gramercyjam Posted June 24, 2004 Share Posted June 24, 2004 Just resurecting this post here to pose another couple of questions: I believe my vac assist is shot. (could be the line/valve looking thingy but I dono..) I was talking to a friend of mine, and he suggested taking the vac assist right out/off the car. IE; mount the master cyl right to the firewall/brake pedel, and just have completly manual brakes. So here's the Q's: Is this possible? And if so, is it advisable? I know I will be dealing with a harder pedel (more leg work.. meh) but I need to know if the system will work properly like this. Anyone heard of this or done it? Thanks. Here's what I did. My problem was I had a lot of trouble modulating the brakes when driving competitively, and ended up locking them up all the time. I disconnected the booster and ran for about a year like that until I was sure I drove better that way. Then I took the booster off and cut it up and used parts from it to make the plate that mounts between the FW and MC, and took the actuator rod and welded a little extension on it so it was the right length. You can adjust free play with the clevis that attaches to the brake pedal. Works great for me. Now I really have to stand on it hard to lock them up and I'm able to modulate much better. The brake pedal is way too stiff for your average driver though so if you do this, at least you have been warned. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted June 24, 2004 Author Share Posted June 24, 2004 Hmm.. well thanks guys for the quick answers there! I'm not sure what I'll do now, but at least I know it's an option. I'll have to check on the price of a new one here (Mid-Ontario) and as for salvage yards, good luck! Around my neck of the woods, all the Z's have gone to that great scrap yard in the sky by now. Eventually I want to go with the Yota 4X4/300zx disks in the front anyway, and got to thinking it might be to my advantage to keep the booster, as oposed to ditching it. And I will go through the whole system again, just to be sure it IS the booster, before I rip into it and start replacing things. Thanks again guys. Quote Link to comment Share on other sites More sharing options...
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