Twisted46

Okay so I now I have speed bleeders on all 4 corners and made some progress with pedal feel. I know there is air in the system because I can pump the pedal up in about 3 pumps. It is now just a question of getting it out.

Still Have Them

NewZed, That is exactly what I ended up doing and it seemed to help some. I have not tried reverse bleeding yet but that is the next step if nothing else works.

Sorry for the long wait for an update, I have been really busy. The speed bleeders from Russell do work. I won't go in to much detail but basically don't buy Dorman brand bleeders for your car, they look identical to the Russell but the nut is lower down and they bottom up on the nut before seating. I noticed the Russell's still had the thread locker on them and I must not have actually tried them. They fit. So I then bled the brakes some more and things seemed to get better but not by much. I also managed to lock up the driver rear caliper now??? So I need to work on that more. I can now pump up the pedal indicating there is air in the system and it takes more effort. I guess I just need to keep bleeding the brakes over and over. Ordered another set of bleeders so I can do all 4 corners by myself. It does stop thought. I'll report back once I get more bleeding done,

I just went through a full energy suspension kit, tie rods, and ball joints too. As others have indicated there are some slight fitment issues with the busing and bearing sizing but nothing that you can't overcome. I personally replaced everything that I needed to remove from the car to do the install including brake parts as the car is nearly 50 years old now and mine sat in a barn for the last 25 of them. The struts are probably the biggest thing that I would not want to go back and do (mainly in the rear). They are not expensive but also not cheap and I think worth replacing if you are not sure. Bad struts will make the rest of your efforts moot. Just beware of the spindle pins :)

I tried to get pictures through the wheels

Good link Miles, I have worked on many brake systems before and the Datsun is definitely living up to it's reputation. I am still seeking out a local club member for a hands on look at things too.

Hi All, Thanks again for the helpful feedback and suggestions. I probably will not have the car off the ground again until this weekend so I can't get a good picture of the caliper, all of the ones I have are not detailed enough. However I did replace the pads with a set that is specd for OEM use and they fit perfect but I will get pictures and part numbers. I will try bleeding again (when I get back to working on the brakes) with the above mentioned reverse flow and removing the calipers (front and rear) to hold the bleeders vertical as the highest point. I could see the orientation of the rears allowing a small air pocket at the top.

I am certainly not ignoring anyone's suggestion to use a larger MC, but if you read back through the posts it was barely mentioned. However before I spend $150 (which is honestly a drop in the bucket at this point) on a new Wilwood 1" MC I would like to confirm that there are no other issues because again, I was having this problem with stock drums and the current front Sumitomo calipers. Stage - 1The front calipers were in good shape when i bought the car so I did not replace them, they are still working great and lock up the front wheels when asked to do so. The pedal felt normal and firm when I bought the car. Stage - 2 I bled the brakes because for all I knew the fluid was a decade old, problems with the soft pedal started. Stage - 3 I then spent the next year fussing over this issue including replacing the rear drums with calipers because I am an idiot and hate drum brakes for no reason. No improvement Stage - 4 The pedal feel got way worse when I replaced the MC last week and I could actual push the pedal to the floor without hassle. Stage -5 Full bench bleed and system bleed this weekend at least put the pedal back to feeling like stage 2/3. I am saying all of this because the problem happened only after I bled the stock brakes and before I started replacing anything.

It is an OEM 7/8 but it feels exactly the same as it did with drum brakes. This started when I first bled the system after buying the car and has existed since.

Okay so I am at least back to ground zero instead of being in the negative. I now have my new MC feeling like the old one (the pedal get firm at the bottom and does not go to the floor). The problem is still that I get a lot of travel before much happen. I noticed while bench bleeding (the way that Miles posted) the first of the two piston strokes is about half the resistance of the second, if that makes sense. I put about two quarts of fluid through it at this point and the pedal does not get any more firm with pumping so I do not think it is air. Two M/Cs with the same issue... Maybe the booster is bad?? the reaction disk is in place. The other issue of PV was solved quite nicely with two unions, no more issues there. I am going to to try and find someone local who knows S30s pretty well and have them take a look, I can't think of anything else.

I know this is outdated but i wanted to chime in and say that I did not use the crossmember spacers and I have 1/2" clearance between my block hugger headers and steering shaft. I did not slot the mouns and the motor is very snug in the back maybe 3/4".

Thanks Miles, I will search and check that too. I did note that the MCs looked nearly identical to each other before installing but who knows. I have spent no less than 20 hours on brakes, is suppose it is on of Z right of passage? like the spindle pins..... and everything else lol.

I have regular bleed screws on all 4 corners right now. I replaced the fronts right away when they were leaking with hardly any fluid in the line and no pressure at all... lol... and I replaced the rears to use the Motive as it does not work with speed bleeders. The plan was to put the speeds back in the rear before the next track day but it sucks I won't have fronts. Sunday I am going to take the MC out for a 4th time and bleed it, delete PV with two line unions, and bleed the system again. I just want to drive my V8 beast 😩

639570 is for the drum cylinders. I have 280zx rear calipers that use the same bleeder as the own fronts. The problem is that 639560 is too short for my fronts and I can't find any longer speed bleeders that are m10x1

I have Dorman 12706 and Z Car Depot 27463 (The Z car bleeders are in a Russell box and IIRC 560 is what they say.) I will double check when I get home. They look identical to the Dormans i bought for the rear. Both are 35mm and the threaded portion is too short for my calipers on the front. Which may not be original I will take a picture when I get home. I bought a 40mm normal bleed screw from the parts store to test and it worked great so regardless the 35mm bleed screws are too short for my calipers. Update: Look like Earls also offers 35mm as the max length in m10x1. The Calipers on my front are Sumitomo and most likely were replaced at some time so maybe they use a deeper port? Ill take a picture of the bleed screw difference tonight.

Thanks again for all the input guys. I do have speed bleeders for all 4 corners. The problem is that the ones I bought for the fronts (Russell) ended up being too short (thread all the way in with out seating so they leak) even though their own site specs them out. They are 35mm which looks to be the longest size for m10x1. The ones Miles linked look like they go on rear cylinders. I have a set for the 280ZX rear calipers and they are actually the same size as the fronts. Maybe Earls has longer ones for the front that will work? I order some m10 unions I plant to use to delete the PV completely for testing. This will all have to wait until Sunday though.

I am going to see if anyone from thr local Z club can come and take a look. I do not know enough about this brake system... Clearly. Anyway I need more fluid and tubing tomorrow to try to bench bleed a third time to rule that out. I am also going to buy some line to remove the PV completely for peace of mind. The problem I have with old fashioned bleeding at the moment is my wife is pregnant and doesn't want to be around "all those chemicals" right now. When I get a friend to come over I was planning to do a final bleed that way.

I think you are right about that..

I messed with it for another hour and still nothing. I need more brake fluid and patience to keep going. The new master is allowing fluid to travel between the reservoirs which does not seem correct. And I bench bled the ports but not the bleeders. I will try all 4 at once when I have enough hose.

Well I installed a new MC and bled everything. The problem just got worse. Edit: I guess I should add more detail instead of throwing a fit and thinking about getting rid of the car again. I installed the new MC and removed the inner workings of the OEM proportioning valve. I then used the pressure bleeder and started at the MC, I did not bench bleed the MC but I used the pressure bleeder on it in the car through all 4 ports, then did the corners. I did not see a ton of air coming out of the line but I did see some, LOTS of fluid movement from the pressure bleeder. The pedal feels even softer than before and now I can actually push farther than before. Also as I bleed one reservoir the other one will start to rise and actually overflowed on my twice (one the front and once the rear). Could an internal seal be shot on this pile?

Hey guys. Thanks for the quick responses. I checked the reaction disc and it is in place. I have a 7/8 M/C as i read it is sufficient with oem front calipers. I still have the 260z prop valve in though. The new M/C will be in today.

I will try to keep it short. Before I started my SBC swap, and rear disc conversion, and suspension rebuild, and... Okay right after I picked the car up and decided to rebuild the rear drums I bled the brakes and have had this issue since then. After bleeding the system: M/C then RR RL FL FR (looking at front of car) The brake pedal was weak when the car was off and would just go to the floor when the car was on. I would get some pressure but not much. I could stop the car though. That was last year and I could not figure it out, blamed it on leaking rear cylinders and decided I was going rear discs anyways. I did not have this problem when I got the car at first... That I can remember considering it sat for 6 months lol. FF to current day and after much tribulation my rear discs (280ZX) are installed. Bled the system as above but used a Motive power bleeder, which made everything go much faster. I still have the same damn problem!! I can push the pedal maybe 2-3 inches with slight resistance And then it gets very firm. I can pump as much as I want with no changes. I have bled the system at least 4 times in the past two days and tried bleeding through the M/C brake line fittings in lieu of bench bleeding. No changes. I wedged a board between the brake pedal and seat when it got to the point of being very firm and went to test each rotor. the rears both spin with little resistance and the fronts were locked up. This mimics what was happening before I had discs in the rear. I am getting plenty of fluid out of each bleeder and yes the are both at the top of the calipers. It really does not seem like I have air in the system as I cannot build pressure with pumping the pedal. This only leaves the M/C so I pulled it to see if fluid was leaking from the rear in to the booster but I did not see any. Also checked to see if the reaction disk was in place and it is. I ordered a new M/C but I am not confident that will solve the problem. Any ideas? Thanks

Yeah not a big deal on the price. I think I paid $150 for them. Mainly want to sell the $600 Nittos on them. I just want to be able to tell someone what they are.

I bought these thinking that my 260 was an early car based on body features. Well I was wrong so I am selling a set a New Vogtland springs I can't use. I also have Stagg struts that are paired with them but I already unbanded them so the struts are extended. $200 shipped for the springs and $250 shipped for all of it.