Quick update. I got all of the brakes on the car, but I am waiting for my Willwood brake bleeder cap to come in. Hope to have it today.




I also got my driveshaft in, and installed.



Lastly I got the last of the intake finished as well.



In theory once I get the brakes bleed I should be able to get it back down on the ground and see if it drives under its own power. Fingers crossed!

 

Waiting, excitedly!

 

Nice work! Just fired my GMW for the first time about 10 days ago. Big moment. Where did you get your driveshaft done? I need that and rear brakes to make it move under its own power.

 

Congrats on getting the engine fired! That’s a big step. There is a company called Drift Motion that sells an adapter for the output flange of the diff that allows you to bolt up a standard 1350 u joint. I also had the same company make the drive shaft. Once I get back to my computer I can PM you links for all the parts.

 

Well I hit a little snag trying to get the brakes working. I put my pressure bleeder on the brake reservoir and found a little leak. Since I had to drain all of the brake fluid to fix the leak I thought I would go ahead and just push the fluid out of the farthest bleed screw. I go to the passenger side rear brake, crack the bleed screw, and ..........nothing. I go to the drivers rear bleed screw and open it, and fluid comes out. Do the same thing to the brakes on the front, and fluid comes out of all the bleed screws. So I go back to the passenger rear and pull the bleed screw thinking the screw might be clogged, and........nothing. So I pull the break line below the caliper and fluid starts coming out of the line. So now I have to pull the caliper and see what is going on. I plan to blow out the cylinder and see if any thing is clogged up.

 

If you ran the reservoir dry, you may have to bench bleed the master cylinder to get it working properly again. Here's a little trick I've used COUNTLESS times to avoid (at all costs) running the MC dry. All reservoir caps have some sort of vent to atmosphere. On the Volvo (threaded reservoir cap) it's a tiny hole right near the center of the cap. If you top up the reservoir with fluid and put a little piece of tape over that hole, no air can enter the reservoir from the top. If no air can get in -- then fluid can't get out; just like putting your thumb over the end of a straw. I've replaced calipers, brake lines (hard portions and soft), etc - you lose virtually no fluid at all from the system other than what's in the component you removed. And the MC/rest of the system) stays completely full of fluid. For next time.

 

Last year I replaced a caliper on my beater Subaru. It took forever to get fluid to come out of the bleeder - and it was even a front caliper, so the thing was only like 4 or 5 ft of line from the master! I transferred the brake line from the old caliper right to the new caliper, master was never even close to drained, the lines to that point were still full of fluid, seemed like it should been easy. But for some reason, I tried gravity bleeding it for hours with no luck, then tried bleeding it normally (pumping the pedal) with no luck. I ended up using my Mityvac vacuum pump thingy (like so) to apply vacuum to the open bleeder and got fluid that way. After that, it bled perfectly normal. I'm not sure why it was so uncooperative initially.

So, if you've got some way to apply vacuum to the bleeder, try that to suck fluid into the caliper.

 

Or.....attach your Motive Bleeder to the reservoir top and put 10-12 psig on it as you would to flush new fluid through the system. That will often push out something that's blocking the flow. I've used vacuum as well, although my all-brass Craftsman hand pump is holding up much better than my plastic Mity Vac did.

 

@Michael Yount since the master cylinder is now dry I am going to "bench bleed" it in the car.

This is the master cylinder I have (see below). I am going to take a piece of hose from the fitting on the front of the cylinder and run it back into the reservoir. I plan to then pump the pedal till are no more bubbles in the line then do what you were talking about and cover that little hole on the top while I reconnect the lines to the cylinder. Do you think that will be good enough to bleed the mater cylinder?

 

One of the things that made me think that there was a clog in the caliper was that I had a motive bleeder on the master cylinder and I had it pumped up to 15 PSI when I opened the rear bleed screw. Also I opened the bleed screw multiple times and even removed it entirely thinking it might be clogged and nothing ever came out. To be honest I never bench bleed the master cylinder, just filled it with fluid, and put the pressure bleeder on. That might be part of the problem. Im going to try and get everything hooked back up today, and then bleed the master cylinder, and see if that helps my problem.

 

Did you ever confirm/find the source of the clog at the rear? Once you get the air out of the master cylinder, I'd hook up the Motive with plenty of fluid in the can and reservoir, pump it up to 10 psig or so, and then work your way around again.

 

I blew the piston out the caliper and there was some sludge in there, and a small rust deposit on the piston itself. I cleaned it all out, and cleaned the piston up. I have the rear brake line disconnected at the rear line spliter, and I was debating on leaving that unhooked, then hooking the motive up, and finally seeing if I can blow anything out at that point. If everything flows good up to that point then I will hook the rear passenger line back up the spliter, and try to blow that line out to just below the caliper. If everything is good there then I will hook the caliper back up, and try to rebleed the system. Did I ever mention I hate brakes haha.

 

If you’re working solo, using the Motive with disconnected lines is a challenge. After bleeding M/C I’d screw it all back together, hook up Motive with PLENTY of fluid. Then go back and just crack the fitting at the splitter. If you get fluid there, tighten it and move to caliper/brake line - crack it, etc. work your way downstream to brake line.

I’ve seen situations where 10–12 psig wouldn’t dislodge crud. But (with Motive disconnected) a knudge on the brake pedal would. Takes two though unless you have the bleed check valves.

 

Sounds good! I will give it a try this evening. Thank you for the input.

 

Okay, so I really need some help.

I went back and hooked all the brake lines up that I had taken off to check for flow, and put the rear passenger caliper back on after pushing the piston out and cleaning the inside. Once all of the lines were hooked back up I pulled the main line off the master cylinder and put a hose on the output of the master cylinder which I then ran back into the reservoir. I proceeded to bench bleed the master cylinder, and the pedal got firm. Once the pedal was firm and the bubbles were gone I hooked the main line back up, and put the Motive bleeder on. I pressurized everything to about 20 PSI and then went back to the rear passenger caliper, opened the bleed screw, and.......NOTHING. I went to the rear spliter and cracked the line going over to the passenger caliper and brake fluid came out! I went to the caliper, and pulled the line from the caliper and fluid came squirting out! I had to pull the caliper to be able to remove the brake line, and when I took the caliper off the rotor I noticed that the pads were clamped tight to the rotor. Also when I pulled the caliper off I could feel the pads squeezing slowly together. I completely removed the bleed screw and no fluid at all came out. All the other brake calipers bleed as they should with no issue. What could be going on here??

It should be noted that when I pressurize the system it holds a steady pressure, and does not drop. Also no leaks have been noticed anywhere.

So after all of that I decided to put the car back down on its wheels and see if I could get the car to move a little under its own power. Before I did this I bleed the clutch which I did through my remote bleeder. I did this by putting a small piece of hose on the end of the bleeder then cracked the bleeder a quarter turn. I then pushed the clutch until the fluid came out clear, and bubble free. I then closed the bleeder and topped off the master cylinder. I hopped in the car fired it up and tried to put it in gear. With the clutch in I could not get the car in gear. I turned the car off, put the car in gear, pushed the clutch in, and tried to start the car. The car would lurch forward like there was no clutch what so ever. What am I doing wrong here guys??

I plan to go pick up a vac pump tomorrow to see if I can pull fluid through the rear caliper.

Any help anyone could offer would be greatly appreciated.

Thanks!

 

I would remove and totally disassemble the offending caliper. There has to be something wrong inside it

 

Clutch - you either have air in the line or when you set up the hydro on the clutch, something’s amiss and you’re not getting enough travel.

 

Don’t understand how you can get a firm pedal during a bench bleed....you’re just pushing fluid into the res - pedal should go to the floor every time...

 

@G Atsma I have taken the caliper completely apart and cleaned everything out. At this point I think I am going to try and just replace the caliper.

@Michael Yount I will try bleeding the clutch again, and see if there is any more air in it. Also I noticed when everything is hooked up (and bleed the best I can right now) the brake pedal starts off soft, but after three pumps it firms up. Is that correct? This car doesn't have ABS.

Thanks.

 

Pedal should be firm first time you hit it. The fact that it takes 3 pumps says you still have air in the system. With the new master cylinder and no ABS, do you have an adjustable proportioning valve that you installed? My thought was caliper replacement as well -- but I'd replace them as a pair in the rear.

Does the clutch cylinder have it's own fluid reservoir or does it share the brake reservoir like the factory BMW set up? On the OEM set up, the 'take off' to the clutch MC from the brake reservoir sits very high on the reservoir -- it's easy to drop fluid level when bleeding below the take off and thus re-introduce air into the system. I did just that once when bleeding the clutch line on one of my wife's 3 E36's she had between 1993 and 2008. To get the air out I had to remove the slave cylinder from the bell housing and invert it so that the bleed screw faced upwards (thanks BMW engineers). Only then did I get my clutch function back. I don't know what kind of clutch actuation you have -- external slave cylinder or internal hyd throwout bearing? If external, if the bleed valve is not facing upwards, you may have to remove/invert/bleed while inverted. If you have a hyd TO bearing -- not only does the bleed have to be right, but you needed to have CAREFULLY set up the dimensions/spacing to be sure you get the travel needed to actuate the pressure plate movement. Another two person job - one person pushing clutch pedal - another looking to see what's moving and how much....