MGB V8 Roadster restoration project Report 147

Transcription

1 16th June The last report ended with me moaning about the late date duel circuit brake and clutch pedal box and the problems I was having with fitting the fixing bolts. In the end with the two bolts that go between the pedal box and the inner wing I resorted to non stainless bolts and washers and used Vaseline to hold the bolt and washer into the socket and then tried to find the hole the bolt was meant to go into. Jobs like this are bloody difficult with varifocal glasses! Some time ago, Nic Houslip suggested using medical forceps to use as a heat sink when soldering on spade terminals. I bought a pair from ebay for about 3.50 including post and packing. I have found a number of uses for them, including holding a split pin when you are trying to fit them in awkward areas such as in this clutch pedal clevis pin. To fit the clutch pedal you have to assemble the centre bush and spacer on the clutch pedal before trying to fit it into the pedal box. To get the pedal arm with its bush and spacer on you need to turn it by 90 degrees to get it up the hole from the footwell and then rotate back to its proper position and hold it there while your assistant tries to line it up in the correct position to get the pivot bolt in from the side of the pedal box. Fiddly, to say the least! The pin punch (drift) helped to get the bolt holes to line up to put the ¼ UNF bolts in from underneath in the driver s side footwell. Once the pedal box assembly was fitted I could get on with tightening up the other end of the clutch pipe. The C-spanner socket came in handy again for this job. I held a spanner on the flexible pipe hexagon to stop the flexible pipe turning. The spanner is invisible in the photo as my left hand was holding the camera! V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 1

2 I thought fitting the vacuum pipe from the manifold to the brake servo might cause a problem. First I blew through both ends to make sure the one way valve was working OK. It should only let the manifold suck the air out of the servo so there is a vacuum in the servo and not let air back into the servo if the inlet manifold pressure increases. Heat from the hot air gun softened the plastic pipe enough to push it onto the plastic union on the servo. It s not a good idea to keep this plastic covering on a stainless steel exhaust! It makes a horrible mess when the exhaust gets hot. When I removed the exhaust on Dugald s MGBGTV8 I found that the MG specialist, who will remain nameless, that had fitted the stainless system, had left the plastic delivery address envelope attached to the exhaust and it had bonded itself to the exhaust in a grotty lump of very hard plastic. I never managed to get all of it off. The brake pipes to the crossmember were made up and fitted. Sorry, no photos, but making one brake pipe is much the same as making any length of brake pipe. With all the brake pipes tightened up it was time to fill the brake and clutch fluid reservoirs with my favourite Ate Racing Brake fluid. I shall now let it settle in the system and check for leaks. Tomorrow I am off to MG Live for the day. It may be Sunday before I get a chance to bleed the brakes. Copper slip grease will help slide exhaust parts together. V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 2

3 LINING UP THE REAR AXLE These stainless steel exhaust clamps are so much better than the U type exhaust clamps that were the norm through the 1960 s to the 1990 s. These clamps are available in different sizes from Car Builder Solutions. With the Frontline 5-link rear suspension you have the two pairs of suspension arms connecting the rear axle to the body in front of the wheels. The 5 th link is the Panard rod that ties the axle on one side of the rear axle to the body of the other side of the car. This stops the rear axle and wheels floating about. The rear wheels need to be in line with the front wheels. If they are not in line the rear axle will in effect steer the rear of the car. The following is a cheap way of checking the alignment with basic equipment. What an earth is Mike doing here? A wire or string line is attached to the rear axle, inboard of the rear tyre, and fixed to an axle stand or similar somewhere in front of the car. With these four legged axle stand you can put some tension on the line by moving the axle stand forward. V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 3

4 Then you get your beautiful assistant to look at the widest part of the tyre and you move the axle stand carefully towards, or away from the centre of the front of the car until the wire or string is just touching the front side of the tyre. It is more accurate if your line is horizontal so that the line is touching the rear of the tyre at the same height above ground level as it is at the front of the tyre. This method is the same as laser alignment but without the expensive equipment. Because you are basically extending the line of the track of the rear tyres to the front of the car it is going to be very accurate as you are multiplying any alignment problems. The string or wire should be as near to, as it can be, to the centre of the wheel. This shows the place I tied the wire on to, on each side of the rear axle. When both jacks are in the correct position so that the wire or string is just touching the side of the front sidewall of the rear tyres, you can then measure the gap each side at the front wheel hub. If both the measurements are exactly the same, the rear axle is perfectly in line with the front axle. Was my original by eye alignment correct? V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 4

5 Who s a happy bunny? I think I ll go and paint some bits satin matt black! If you ever want to paint return springs, this method works well. Get a block of wood and fit some screws in, wider apart than the spring ends, so that when you fit the spring between the screws it is stretched. The paint will then spray the coils inside the spring rather than just the outside. These are the clutch, brake pedal return springs and the spring for holding the clutch flexible pipe away from the oxygen sensor. Measuring the gap between the front hub and the wire. 92mm Well I can t complain about that. To move the Panard rod by 0.75mm would be impossible. One turn on Panard rod thread either way would increase the error. Two of these exhaust tail pipe finishers came with the project car. I got Jane to take a photo so that I could see what they looked like. I don t think I will bother with them as they do look a bit too Boy Racer ish. I do have a bit of a dilemma with the exhaust pipes from the silencers rearwards. The exhausts tailpipes I had made went over the rear axle and along each side of the petrol tank. V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 5

6 It appears now that these will not fit with the Frontline rear suspension. I can come straight out of the rear silencers; bend the stainless 2 diameter exhaust pipes up 10 degrees underneath the petrol tank and exit the underside of the MG. The problems I can foresee with this scenario are: the heat from the exhausts will not help with keeping the fuel cool and the other problem maybe ground clearance. HAND BRAKE CABLE FIXING FOR THE COMPENSATER I machined down one end of the rod so that the springs would slide over and threaded the end at 5/16 UNF for the lock nut. I may have mentioned this before; bare with me if I have, remember I m old. I did overhaul the brake cable that came with the car. When I came to fit it I found that the area at the front where the inner cable enters the outer cable was a bit sticky due to the plastic coating of the inner cable had split. I looked up in the Moss catalogue and was amazed to find a new cable complete with the rear pull rods was only plus VAT. For that price it was just worth using the old cable. Originally, the compensator part of the handbrake cable has a flexible fixing to the rear axle with a bracket for two fixing bolts on the diff casing. A reinforced rubber strap then connects from the diff casing to the hole in the handbrake compensator that you can see in the photo above. I decided to totally redesign this method of mounting and use the spare bracket on the Frontline rear suspension for the Panard rod, which is not used for anything. Rather than rubber for the flexible connection I decided to use a rod and two springs so that the compensator could move left or right as need be. The springs would fit either side of the hole in the compensator bracket and be fixed in place with a 5/16 UNF Nyloc nut. On the other end of the rod I would make a fixing to fit to the 3/8 clearance spare hole already in the Frontline bracket. I found a suitable length of rod of about the same diameter as the outside diameter of the small compressions springs I was intending to use. I cleaned up the head of a 3/8 UNF bolt and set it up in the vice to weld the rod on to the bolt head. Before I fully welded the bolt to the rod I tacked it and assembled all the bits together to check it worked. It did. I then took it off again to weld up, blast and paint. I did my usual over the top treatment of Kurust, etch primer, normal primer and then top coat. V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 6

7 BRAKE & CLUTCH PEDAL RETURN SPRINGS The newly painted brake and clutch pedal return springs where fitted. It is easier to fit the springs onto the pedal arm first and then the pull the other end of the spring onto the welded on rings that are on the flat part of the inside of the bulkhead. The bits to paint hung up and sprayed with primer and guess what? Satin matt black aerosol paint! BOLTING UP THE SUSPENSION I wanted to tighten up the front suspension when it was loaded with the weight of the car. Rather than grovel about underneath with the wheels on the ground I had a light bulb moment. If I jack the suspension up so the car comes slightly off the axle stand that is under the chassis rail, the weight will then be on the suspension and it should be more or less at the normal ride height. The modified handbrake compensator mounting with the springs and shaft coated with copper slip grease. The suspension jacked up ready to tighten the suspension pivot bolts. V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 7

8 BLEEDING THE BRAKES The idea of the system is that it uses the pressure of a tyre to push the brake fluid through the master cylinder, the brake lines, calipers and wheel cylinders when a bleed nipple is cracked open. Bleeding the braking system using the Gunson EEZIBLEED system is quite simple and does not entail having to pump the brake pedal. Looking on the internet a moment ago, to check they were still available, I found the kit available for as little as 16. The bottle to the left of the above photo is the reservoir that you fill with new brake fluid. You find the appropriate cap to fit your master cylinder and attach the cap to the clear plastic pipe as per the instructions. RTFI (Read The F***ing Instructions). It is important that you have no more than 20psi in the tyre you are going to use as the pressure source. The kit comes with three or four different size caps to suit most brake systems. In the kit they supply short lengths of various diameter soft plastic piping to fit the various size bleed nipples. In my opinion these are too short. V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 8

9 Yet again that little Snag has given me a problem! The leak was coming from the joint where I had used the copper pipe kit from Automec that came with the project MG for the brake pipes at the rear and where I had connected a Kunifer pipe to extend the brake pipe to master cylinder outlet. Easy problem, I thought, just tighten up the unions. I did, and the thread stripped on the brass nut on Automec copper brake pipe! Bleeding stopped for the day and I placed my bleeding container to catch the drips. To stem the flow and attempt to not empty the brake fluid reservoir on the master cylinder I placed a small piece of kitchen cling film over the opening for the brake fluid filler cap and then replaced the original cap. I will be able to see tomorrow morning whether or not this worked. If it doesn t, and the brake fluid reservoir is empty, I will have to bleed all the brake bleed nipples again after I have replaced the pipe and union. I modified a plastic container that I use to catch the brake fluid when the valve is open. If the container is clear plastic you can also see when the air bubbles stop coming out of the system. When you have no more bubbles, that part of the brake system is clear of air and you can tighten up the bleed screw. Now this is what you don t want. A leak on a joint! TO RECAP BLEEDING BRAKES WITH THE EEZIBLEED 1. Top the brake fluid master cylinder reservoir up with brake fluid. 2. Connect the correct cap to the EEZIBLEED clear plastic pipe. 3. Make the area clear around the calipers and rear wheels so you can undo the bleed nipples easily. This may include jacking up the car, putting axle stands under, and removing all the wheels. 4. Check that the tyre you are going to use as an air pressure source is close enough to the EEZIBLEED system and the master cylinder. 5. Check that you have no more than 20psi in the tyre. 6. Fill up the EEZIBLEED reservoir with brake fluid. 7. Connect the suitable EEZIBLEED cap with the clear plastic piping to the top of the master cylinder reservoir. 8. Put some paper towel or cloth around the master cylinder reservoir in case you have any leakage of brake fluid. 9. Connect the black plastic pipe to the tyres inflation valve. 10. The system should now be pressurised and you are ready to bleed the brakes. 11. It is good practise to start with the bleed nipples that are furthest away from the master cylinder and work your way towards the nearest bleed nipples. 12. Open the bleed nipple until you just have brake fluid coming out and no air bubbles. 13. It is advisable to have an assistant watching the EEZIBLEED reservoir to check that the brake fluid level does not go below the black line on the side of EEZIBLEED container. When it gets near the line. Stop bleeding release the pressure by taking the black valve connection off the tyre and top up the reservoir. 14. When you have successfully bled the brakes the brake pedal should be hard. 15. Pour any UNUSED brake fluid that is in the EEZIBLEED reservoir back into you brake fluid tin. Clean up the EEZIBLEED kit and put it back in the box for use next time you need it. V8 Register MG Car Club V8-restoration-Mike-Macartney-Report-147 9

10 The clutch can also be bled using the EEZIBLEED system. To start with, I cut two lengths of 2 x 1 box section. The length of these box sections were approximately the outer diameter of the tyre diameter (26 ). I made sure the ends were square and both exactly the same length. I scribed a line across the midpoint. One box section was clamped to each brake disc with the centre line on each box section in line with the hub centre. Photo showing the minimum level of brake fluid in the EEZIBLEED reservoir. Work on the brakes came to a halt as I needed to order some brake unions to remake the brake pipe connection to the rear brakes. I got on with tracking the front wheels to get the wheels pointing roughly in the right direction. It will be interesting to see how accurate my method is when compared to some pucker expensive workshop alignment equipment. ADJUSTING THE TRACKING Before I started the above measuring I removed the wheels and jacked the MG up and moved the axle stands to under the front suspension lower arms and used some wood to protect the paint and spread the load. By having the car resting on its suspension I assumed that the body would be as it would as if it was on its wheels on the ground. I then measured the distance between the front pair of box sections. Previously, I had screwed the track rod end, on each side; in as far as they would go. I marked the track rod and the track rod end with a horizontal line and rotated each track rod by one turn and then measured the distance between the fronts of the box sections again. One turn on each track rod shortened the measurement by 6mm. TO BE CONTINUED IN REPORT 148. After my visit to MG Live on Saturday I found out by looking inside an RV8 bonnet that the reason I was having so much problems getting the MGB pedal box to fit was that the metal clutch pipe comes out of the clutch master cylinder further forward than the MGB clutch master cylinder, that has the outlet right at the back by the bulkhead. I am surprised now that I even managed to get it to fit. I enjoyed meeting fellow members at the V8 Register marquee and I must thank, especially Debbie for her sterling work, serving the refreshments in such hot weather. I could only be in marquee for about half an hour before my head started leaking and the sweat was pouring into my eyes. Debbie was probably there all day. Many thanks to the other members who made the V8 Register marquee a pleasant place to come for a pint of Hook Norton and a sit down out of the burning sun outside. I am sure there were less trade stands at the event this year, when compared to two years ago on my last visit to the show. I did manage to pick up a few bargains but went home with only a little dent in my wedge that I took in case I found a lots of things to buy. Jane was pleased that she still had some money left in her purse! You can me at: mikemacartney@btconnect.com with any hints or tips which may help me, or other V8 Register members. 20th June V8 Register MG Car Club V8-restoration-Mike-Macartney-Report