Bilbo's mk1 Cavalier

One question, brake fluid reservoir, does it need to be above the master if I relocate it? I'm sure can make that work, but wasn't sure if it was important that it could gravity feed to the master cylinder or not? Or will the master cylinder simply suck in the fluid it needs regardless?

I think you will have a nasty air bleeding issue if you position it lower and it might overflow (communicating vessels) but that is just my basic physicks thought.

Thom

Perfect, thanks both. After doing some more reading earlier it seems this is the consensus from everyone. I got my mate at the workshop to pull the reservoir out of my mk1 5 I'm breaking and measure the ports for me. Now purchased some 13mm push connectors and hose to relocate the reservoir. Plenty of room above the master cylinder so this should be a simple job, just need to make up a bracket to hold the reservoir.

Excellent addition, I bet it sounds awesome now

Obviously with the booster removal you'll need to shorten the actuator rod as well, I ended up moving the mounting point on the pedal to give a bit more mechanical advantage - I've read a pedal ration of 6.5-7:1 is best for non servo brakes.

You say the brakes are a bit soft. Did you bleed it another time after a bit of use? Could improve that.
Thom

Ok, so we've sorted a load of stuff re: the brakes. More to do, but it's been a lot of hours the last couple of days, not the most fun experience haha.

So I started by removing the brake booster/servo from the car. Simple enough. Then made up a plate out of 5mm ali which bolts through the original 4 servo mounting holes, with 2 additional holes for the master cylinder to bolt on to. Offered up the master cylinder and it sat nicely. Actually with the thicker plate over the firewall a noticeable amount less flex on the brake master when being operated, which is good. Made up a pushrod pin to thread into the original brake pedal clevis, and got it all bolted down.




Lines are ugly but this was just to test it out to see if it would work. It did work, but my god it was terrible haha. Using an MX-5 brake pedal, so 4:1 pedal ratio, and as it turns out as this is a 2001-2005 MX-5 master cylinder, it is 1" bore. The pedal was so hard it was just disgusting to try and use. I drove home, and then back to the workshop and ripped it all off and started again.

This time I opted for a 5/8" master cylinder. Less fluid displacement, but way way less pedal effort required. The brakes on this car aren't exactly massive, front calipers are small and the rears are only small drum cylinders, so the 5/8" master seems plenty to make them work as intended.

So I made up another plate for the new master cylinder, and bolted it onto the firewall again. Working in driver's footwell in any car is never elegant, not a nice experience haha. Needed another pushrod made, but this time something a little slimmer to fit the master piston. So me and a mate modified this bolt, chopped the head off, cut it to size, and then clamped the threads in a drill. Ran the drill flat out and gently skimmed the non-threaded section up and down with a flap disc on the grinder. Basically like a makeshift lathe. Rounded the end off for a smoother contact patch when we were done. Worked a charm, looks good I reckon:



That threaded straight into the brake pedal clevis no trouble, and I adjusted it so it just has a tiny fraction of movement before engaging the master cylinder, then tightened up the lock nut. All done.


So back to the engine bay. We made a mistake, well I did. My tee piece brake splitters, we obviously undid everything and had to re-bleed the braking system. Well I modified the front lines, re-flared and stuff. Everything leaked badly. Stripped out a brake splitter trying to do it up too tight. Basically had a nightmare, my mate stuck it out with me until after the sun came up to get it done haha. Anyway turns out the splitter wanted a bubble flare, not a double flare as I had been making. Ffs, literally just me being an idiot and using the wrong flaring tool. Oh well, it's done now.

Spare trumpets on and with good clearance now:



Need to finish some wiring, tuck some wires away, TPS wiring needs re-doing properly, it was just twist and taped here as the genuine TPS arrived and I had to re-wire it again and get that calibrated.

Also note my throttle cable bracket we made, bolted to the throttle bodies this time! In my tiredness last week when first fitting these, I very stupidly made a throttle cable bracket that had a chassis mount point. Awful, can't believe I overlooked that. So when the engine jolts over a bump, leans on throttle etc. the throttle bracket didn't move with it. Hence super jerky throttle cable. Now fixed, it's like a different car haha.




So much room for big trumpets now! Can't wait to get some monster ones haha. Going to redo my brake lines again, neaten them up properly, and while I'm there put a bias valve in for the rears, which I've been meaning to do for ages now.

Anyway, the brake pedal. It's lovely now. No servo, no problem. It's not rock hard at all, and has good brake pedal feel, plus I have a ton more room in the bay, which is great.

So, brakes. Again. The setup I had after the booster delete was just awful really. Not good, pedal too hard, everything a bit janky, it didn't leak but that was about all it had going for it.

I spoke to a mate who helped me with a load of questions I had re: converting to dual master cylinders. So I decided to bite the bullet and just do it. I will pre-face this by saying another all nighter occurred during this a few days ago, and it really was a lot of research, reading, measuring, cutting etc. to get this done.

So we start off with the balance bar:



This is a balance/bias bar from Compbrake. Doesn't cost much, and in all honesty has done the job perfectly well.

Had to get a couple of holesaws, the smaller of which to cut the pedal. Due to several different space constraint reasons I couldn't really raise my pushrod pivot point by much more than 13mm, so I marked 13mm up on the pedal from the original clevis lock pin point, drilled a pilot hole, and got the pedal cut for the balance bar centre tube.



A good fit:



Why this far forward jutting out and not further back in the pedal? I didn't want my pushrods to be too long and when measured and mocked up this was the best spot for it.

Not exactly the most godly welding you've ever seen, but that isn't going anywhere I can assure you haha.



The inside didn't warp and the centre spherical bearing still slid in smoothly.

So, onto the master cylinders. I had approx. 4.25" of space from the firewall to my cylinder 4 trumpet. That really isn't much. One dual circuit master cylinder was totally out of the question. So 2 single port master cylinders were all I could fit. I looked at various options, weighing up quality and cost. The Wilwood compact masters seemed like an absolute no brainer to me, really inexpensive, and only 4.1" long from firewall mount point to the end of the cylinder. Just small enough.

Went with 0.625 bore for the front, and 0.70 bore for the rear, seems to be around what most resources recommend in general for a non-servo dual master brake setup.

Now onto the pedal. It's a mk2.5 MX-5 brake pedal box from the car I sourced the engine/loom and just about everything else from. Well it was once. I already lopped off the throttle pedal portion a while back. Bolt pattern on it to mount through the firewall was 60mmx80mm, too big for what I needed now. With the balance bar set up with the clevises in the recommended position (just a few mm away from the centre tube on both sides) I needed the master cylinder through bolts to be 67mm apart, and the master cylinders use what appears to be a standard bolt spacing of 57.1mm for their 2 mount holes. So I welded up the original holes in the pedal, and drilled out new ones. Again 13mm higher, I wanted the pedal box in the exact same position in the car, and this would keep the raised pivot point on the pedal in line with the pushrods on the Wilwoods.

I then used a larger holesaw in the centre of each pair of mounting holes, and drilled through to allow both new master cylinders to slot through:



Note the spacers between the masters and the pedal, these were on the original pedal box, but I cut them off to make them a little shorter when I first made the original setup last year. We tacked these securely back in place once we were happy with everything.

They both slot through nice and straight, 67mm apart as required by my balance bar.



As you can see, a lot was cut off of the pedal box, so after this I added various bracing on the sides that angle up to the top, reinforcing the firewall face to the pedal mount part of the box. I also double skinned the front of the pedal box as I had removed the brace points on the inside, just to make it a bit stronger. Felt nice and sturdy.

I needed as much engine bay space as possible, so I binned off the 5mm ali I used before and went with a thinner piece of steel. Much less soft than ali of course, but still works well as a bit of a load spreader plate type thing. Initial test fit:



Of course I had to re-drill the firewall with the new bolt spacing, and holesaw the 2 new holes for the master cylinders. Again 13mm higher than before like the other bits, to keep the pedal box exactly where it was previously.

When we were happy with this I got the pedal mounted inside, made up a sleeve and lock/jam nut for the balance bar, as Compbrake supply a remote adjustor cable for this balance bar separately, which I didn't go for, they don't include a lock nut. Was fairly simple to sort, I just had to go to a nut and bolt store to get a 7/16 20 nut, because apparently every chain hardware store literally only sells metric "M" sized stuff and literally no packs of imperial nuts. Oh well, it was 44p for 2 haha. Used a couple of very large washers between the clevises and the centre tube as recommended by Compbrake's fitting documentation, seemed to help a lot with keeping the clevises level and behaving, so I'm glad I did that.

Brake lines were of course a total nightmare and took 2 days to sort out. Everything was done and then re-done again, this time it all seals properly, and not for lack of trying. A load of new unions, T pieces etc. Put a lot of hours into those bloody brake lines, thankfully a couple of mates helped me out a lot. We got it all bled, worked out a reservoir solution for the time being, and here we are:






Just about short enough to clear the trumpets.



Still using the MX-5 brake reservoir for now, it has a divider at the bottom so if one cylinder/line fails, the other still has fluid up to the MIN level, which is good for now. But I am going to buy either a large single reservoir with completely isolated dual chambers, or 2 completely separate reservoirs. It will mean re-bleeding, but re-bleeding can't hurt, probably worth doing it again anyway.

The pedal feels so much better. It's softer on initial braking now, so light braking is a lot nicer even with no booster now. When more braking is required the force is obviously higher than before when it was assisted, but it is a manageable amount of foot force, you don't have to brace your back into the seat and stand on it. Completely independent master cylinders too, so nice and safe, and with enough fluid displacement between them to power any potential brake upgrade I may do in the future. Seems funny running this setup with original front calipers and NOS pads, and rear drums, but in the long run this is the hard part, and it's now done and can be left alone, save for any adjustments to the balance bar, which can be done without disturbing the master cylinder or brake lines at all of course. But god it was a total slog to get it done, and honestly if I never have to deal with a leaking brake line ever again in my life I will honestly be so happy. Horrible job.

Anyway the car is great now, bigger trumpets will be sorted soon ( I measured and have clearance for approx. 110mm trumpets) as well as the heatshielding I mentioned before. No filters are planned for them, this is a £200 engine. If a stone goes in, a stone goes in. We die like men.




I absolutely love this car.

Ah mate that's the dream, knowing there's parts out there and being able to go and check/measure all the different possibilities. I think for me I'll probably fit the earlier type 2 pots that came on the earlier year Cavaliers, people say they're better, less prone to seizing etc. MantaSport do a caliper conversion kit to run MK4 Astra calipers on the rear, only thing is I'm not sure they'd fit under 13s. I don't really want to run bigger wheels as I love small wheels on old cars. We'll see.
Haha cheers, now I've broken the 5 for parts it's a case of it needs to be done or I don't have a car and have to rely on borrowing my girlfriend's Alto 😂 so there's the motivation to get each job done in a day when I can, so I can actually get home from the workshop haha. It's been a lot of learning so far, but it's great, it's given me a lot more confidence to take on any job on the car now.

Hey, good to see another being saved. So in terms of parts, I got them from here there and everywhere haha. You may struggle for certain things to find parts that are listed for mk1 Cavalier, but I found a lot of parts listed for a Manta B also fit, as they're essentially identical underneath.

The 2 main things I recall to be careful to order the right parts were front brake pads, and rear drum cylinders. The pads on the front are dependant on the year of car, and the rear cylinders seemed to be offered in different sizes (I ordered the wrong ones at first). I found it easier to remove the parts I wanted to change and compare them to the photos on the ad sometimes, check the parts look like the same fitment, check any measurements are the same etc. Same with the discs actually, I measured the diameter of mine and made sure the new ones were the same size before ordering.

I got some new old stock stuff from eBay, I also found AutoDoc and similar parts websites stocked a load of stuff, just be careful with AutoDoc as I noticed some parts in the listings clearly didn't look right. The lowering springs I got from eBay, shocks from AutoDoc. Shocks fitted fine I just had to put some little spacer washers on the lower mounts as the new ones had slightly smaller bushes that weren't quite tight in the mount.

Pretty sure I got the ball joints, stabiliser links, and brake caliper slider pins from eBay. There's a load of stuff out there for them, just takes a little bit of time working out what parts will be right as there seems to be some variations on what is offered. Overall though other than exterior panels I've found most things can be found without too much trouble.

Also just one thing to note about brakes, be careful if yours are old and original as the pad material is likely made with asbestos. I drenched everything brake related in brake cleaner to make sure there was no dust, I also drenched all surrounding parts like the drums themselves etc. in water, and I wore a full painters respirator when I was removing the originals, not worth the risk!

My water temp gauge has never been correct, due to the sensor being the original Mazda one, and the cluster being the Vauxhall one. Incorrect resistance that needs sorting. Anyway regardless of that, it doesn't actually give a number reading, so I've always wanted to get a proper one that does. Again an inexpensive gauge was purchased, as well as an 18mm water hose joint to locate the sensor.

Some people fit these on the front radiator hose, but as this is near the thermostat, when the thermostat isn't open it won't give a true reading. So I went with the heater matrix hoses that most people recommend to use on 5 engines. Pretty simple, I just drained the coolant, cut about an inch out of the pipe, and popped the sensor joint in. Made sure the gauge came with a 1/8 NPT sensor, which it did. It threaded in nicely. No leaks, and fresh coolant put in, all bled and happy. Can't complain.




Yes there are 2 manifold nuts missing in the background, I'm sorting out some dodgy stud threads haha.

Anyway, due to the large amount of loom under the dash, I have never connected up the eye vent pipes, meaning the eye vents have no function. So I popped the other centre one out next to the AFR gauge, disassembled the disc part that allows you to open and close the vent, and slotted the new gauge into the surround. It fits very snugly. 




Tapped into the wire to allow it to only illuminate when the light switch is turned on, and it's sorted:




And it works. Sits bang on the correct temperature and appears to be functioning perfectly, so I'm happy. Just a little extra peace of mind over the vague OE temp gauge. I must concede that the rev counter is a little too bright at night. It's not horrendous, but it is slightly uncomfortable haha. Oh well.


Got some other bits I want to do, but money is a little tight at the moment, so I'll likely end up doing some maintenance jobs I've been putting off for a while.