I was not looking forward to starting work on the car today, bad night sleep coupled with the fact I knew I would be spending the day in various positions of major discomfort kind of put me off even wanting to get started. None the less, once more unto the breach dear friends?
Started by getting back under the glove box area and having a close look at the linkage setup and just how the booster was held in place. The booster itself is bolted through a plate that is bolted to the unused steering column support. The plate is sandwiched up against the firewall and the threads pass through the firewall from the booster and the whole lot is sandwiched together with 4, 13mm nuts. With the booster unbolted, I suddenly realised there is a huge lack of space between the firewall and the inlet manifold, even with the intake removed and a bunch of stuff out of the way. It was going to be a tight fit to get the booster and master cylinder out as one unit.
I grabbed my vacuum bleeder and sucked as much brake fluid out of the reservoir as I could, then I took to removing the hard lines one at a time, again sucking as much fluid from them as I could with the bleeder. For reference, a non ABS, 4 wheel disc E30 seems to use 3 ports of the master cylinder, two for each of the front calipers and one line for the back which runs via a portioning valve. Should make life kind of easy when it comes time to do the hard lines again. Think ill remove the portioning valve and run a new hard line right to the fitting, then use a “T” piece to join the front lines to the master as the new masters only have single ports. With the booster free from the firewall, I turned my attention back to the linkage.
The way the linkage fits up is pretty simple, a bunch of pins and retaining clips hold everything together so it can turn and twist in various directions. Pry the clip up, spin it around and it will slide off the pin, then you can punch it out of the knuckle and disconnect different parts of the linkage. Pretty simple, just a little bit fiddly. On this side of the car there are two joints that allow the rod that connects both sides of the linkage to pivot on what is basically a hinge, depressing the rod on the back of the booster. You need to knock the pins out of both of these joints to allow you to remove the plate that holds everything together.
With the pins out I dropped the end off the booster and returned to the engine bay to see if I could manipulate the booster enough to clear the inlet manifold. This is actually pretty difficult, even after removing the C101 plug from the firewall to give a little more space. It might seem like it can’t be removed, but a combination rotating the booster, pulling forward, while tilting the back down for the push rod to clear the firewall seems to have done the trick. There was quite a bit of swearing and a whole lot of head scratching because there was no way in the world I was going to remove the inlet manifold to get this out. I was nearly about to remove the push rod from the booster (pro tip for next time maybe?) when I thought I would give it another try. *POP*, another one of those moments when the planets seem to align, the sun is in the correct orbit with jupiter and the moon is slowly rising from the east, all coinciding with removal of a stubborn piece of equipment.
With the booster and master cylinder removed, all that was left to do was unbolt the 2 remaining bolts that hold the bracket to the steering column support and yank the bracket out… It was at this point that I realised I hadn’t removed the pin off the rod that connects the other side of linkage (my advice above corrects this error in judgement), so now I had a big steel bracket flopping around a hinged joint that just wouldn’t slide out from the bracket no matter what position I moved it to. Sigh… this made the job so much harder because I couldn’t get a screw driver in to pry open the clip and pull out the pin, fingers to the rescue! a few curse words and a little blood later (those clips are sharp!), the pin was removed and out came the plate.
Next it was time to focus my attention back to the drivers side and the mess of wiring that was waiting. You know, I’m going to rant here because I’m sick of shoddy wiring causing problems in cars, especially cars I own or end up working on. Learning to solder is easy, especially doing simple wire joins like this, it is about as easy as it gets. Take some time and learn, you should have it down adequate enough to complete solid joints on wiring like this in about 3 mins. Twist both ends of wire to bunch the strands tight, then make a hook with each piece of wire. Take the two hooks, hook them together through the middle and twist the free ends around the wire back up towards the insulation. If you do it right, the wire starts to take on a braid pattern that is VERY difficult to pull apart. Next, turn on/set iron (make sure you are using a wide tip) wait till hot, then flow a little solder on the tip and place it under wire joint to be made. Grab your roll of solder, break off a piece about 3 inches long, then feed the solder into the top of the joint, NOT into the tip below. The trick is to have the wire you are joining heat up and the solder melts through the joint from the top. Too many people try to melt the solder on the tip and glob it on the wire. This usually doesn’t work and almost always creates dry solder joints. You can either tape your joints with electrical tape, or for a professional finish, use some heat shrink insulation. Just select a size about 2-3 times the diameter of the wire you are working with, then cut off enough to completely cover the soldered joint, leaving enough to shrink over the insulation. Slide it over one side before soldering and make sure to keep it well away from the joint as radiating heat will shrink the tube before you get a chance to slide it over. It shrinks easily from a heat source such as a lighter or a small butane torch. Seriously, google hook or J method, you’ll find a bunch of DIY’s showing you how to solder with this method. <End rant> Now, where was I? Ohh yeah, terrible wiring. First thing I did over this side was pop out the ECU and tie the cable back out of the way
Incidentally, 320′s use the same ignition and fuel system as the 325i, the difference being a lower pressure fuel regulator, given the 320i doesn’t need as much fuel as the 325i. Awhile ago I converted to a MAF sensor from Miller Performance and upgraded my ECU to a later model “173″ unit from a 325i so I could take advantage of the chip Miller offer for 19lb injectors (this was all back when I was just going to run a 2.7L and drive this daily. How things change eh?). End result? the 320i purrs like a kitten, no problems at all running the 325i computer, including 19lb injectors. Back to my mess of wiring. The really old, wise man who taught me the basics of electronics showed me this method for anytime you have to cut a wire (say to neaten a spliced section, or to relocate or shorten a section, etc) that you have no idea what it’s purpose is. Simply tape each section of wire that is spliced together and label it with a number, then go about the rest of your job. Wires to be spliced together all share the same number, so use a different number on each of your cuts. When it comes time to solder wires back together, even if you don’t know what the wire does exactly (and you can’t be bothered to trace it back, haha), it’s simply a case of matching numbers, 1 with 1, 2 with 2, and 3…. well, 3 sounds like a great time
With wires cut and loom tucked back out of the way, finally got a chance to have a closer look at the factory pedal box. Kind of complex, no doubt due in large part to the RHD linkage setup, but basically pedals running on a cam (bolt with a sleeve around it), a couple of return springs AND THE MOST STUPID THROTTLE PEDAL EVER KNOWN TO MAN! OK, I might have been a little rough, but really? talk about way over complicated. Instead of doing something similar to the brake pedal, BMW decided they wanted the throttle cable to enter from the OTHER side of the pedal box, nowhere near the throttle itself. So what did they do? pressed a piece of round bar into odd shapes, welded a plate to the bottom of the pedal box with a couple of stays attached, then thread this bent round bar through the stays and connected one end to the top of the pedal, and the other end to a cam, which the throttle cable clips into. On each of the stays is a rubber bush (or it was, 15 years ago!), or if like mine, a whole bunch of play with nothing holding the round bar in place but another one of those bitch clips on the other end of the shaft. No wonder I could tap dance a tune on my throttle pedal.
If you can tap out a routine to make the lord of the dance blush, chances are one or both of these rubber bushes is gone in your pedal. I’m of course assuming ALL E30′s are like this (though LHD cars might not be as retarded), given how simple BMW likes to make their chassis and how overcomplicated they like to make their components, I wouldn’t be surprised if they are all the same. One bush each side, along with the retaining clip on the left side to stop the shaft from sliding through the stay. Replace them, they are cheap and I can assure you, yours will not be supple rubber anymore.
This insanity out of the way, I wanted some more space to work on the pedal box as the mounting plate used on this side is quite large. This means I wanted to pull the AC hoses up out of the way, or remove them totally, but this isn’t the easiest of jobs to do with the heater box still in position, so I’ll settle for moving them out of the way for the time being. Pretty simple, if you haven’t used your AC in years, chances are you won’t have any gas left in it, so go right ahead and remove them. If you have gas in yours… you SHOULD call someone to come and evac it for you, they can reuse it when you refill, but…. Ahem.. Go into the engine bay and look for the bonnet guide on the right side.
AC hoses join behind here, small hose is a 15mm and 17mm, large one is a 24mm and something so large it requires a shifting (adjustable) spanner as I have nothing larger than 24mm in my kit (its 27mm FYI). Remove the guide to make it easier, I recommend marking the back side of the bracket where it mounts to the body and the top side of the washer on the bracket to help with realignment. Or you can just whip it off and put up with the noise it will make afterwards when you refit it, your choice.
Lines disconnected, it’s easy to just pull them through from inside the cabin, they are held in place by a rubber bung used to keep the water and dirt out, so they will usually pull the bung out of the firewall as they come through. No big deal you can slide it back over the fittings and place it back into the firewall, just use a little lubricant on the holes to help slide the AC lines back through when refitting. I suspect yours will be like mine (ie, original) and kind of perished, so id replace it while there if you can, just to keep the weather out and stop any chances of rust forming.
With the lines pulled through and my mess of wiring out of the way, I could finally start unbolting the 7 (roughly?) 13mm bolts that hold the pedal box to the firewall. A couple are hidden by the carpet, so if you find you can’t get it free after you think you pulled them all, double check to make sure you didn’t miss one hiding somewhere. Before you pull all the bolts out, I recommend you start by removing your brake (and/or clutch) pedal from the box now to make room later as the plate is rather large. They are only held in by one 17mm headed bolt that passes through the pedal and the plate, so they are pretty easy to remove now, rather than struggle later. With the pedals out and the remaining bolts removed, the plate could start to move around on the firewall, but before I could remove it I needed to do a couple last things. First up, the other end of the rod that forms the linkage between the sides is attached with another cam and pivot setup like the other side. That means driving out the pin just like we did on the passengers side, so hop to it now.
With the pin removed, take a 17mm spanner and loosen the lock nut on the shaft, then go back over to the left side of the car and unwind the rod, which will remove it from the linkage on the opposite side. Once it is removed, you’ll find you can’t actually pull the rod out from behind the heater box as it is way too long and far to stiff to make the bend back out the passenger door. What you do with it is up to you, I’m thinking of taking to it with a grinding wheel as it will no doubt create a rattle if left behind.
Wth the rod removed, use a pair of pliers or a wide flat blade screw driver and push the rubber bung out of the metal plate that attaches the throttle cable to the shaft, then follow the round bar across to the throttle pedal itself and pop the circlip off the end of the bar that passes through the top of the pedal. You need to do this before you try to remove the plate otherwise you are going to be trying to open your throttle when you try to pull the plate out. Now, if you removed the brake light switch plug before, there should be nothing left holding the plate in place and you can give the plate a stiff pull towards you. It should start to come free from the firewall, but maybe a little stuck as it uses a fibre gasket around the back side of the plate to seal.
The plate should now be coming away from the firewall, take a pair of long nosed pliers and squeeze the sides of the clip that holds the throttle cable to the back of the pedal box. They have a couple of lugs on the side, so if you squeeze them in, you should be able to push the clip (and cable) back through the pedal box. With this done the pedal box should be free from the firewall and is simply a matter of moving it around to clear various parts under the dash area.
Finally, linkage has been removed from the car! What a task.