Overview

This blog is intended to document the build of my Gardner Douglas Mk4 Cobra; partly as IVA evidence, bit primarily to help others learn from my mistakes and/or successes.

I will endeavour to post as often as possible, with a view to entering a single post for a particular element of the build process, however inevitably some things may not be completed in one go. All posts will be tagged so it should be easy enough to find the information you seek.

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Showing posts with label brakes. Show all posts
Showing posts with label brakes. Show all posts

Saturday, 2 September 2017

Rigid Brake LInes

The rigid brake pipes come coiled as a kit already flared with the fittings installed, these were uncoiled and straightened by stretching them between myself and a friend.  The shorter of the two is for the front and the longer is for the rear, the kit also comes with a couple of 'T' pieces and the flexible hoses for each brake.

Front brakes
The 'T' piece was loosely bolted to the pre-installed rivnut adjacent to the lower diagonal brace mount, this was tightened fully once the pipework was complete.  Starting at the front a handheld pipe bender, I created the first bend then offered it up to make sure it was right before continuing with the next.  This process was repeated until all the bends were complete.

The pipe route is shown in the pictures below:
From 'T' piece, along lower frame and under engine mount...

...continues along lower frame then up round tube to aluminium block.

The flexible hoses are different lengths, the short one goes right and the long one goes left

Rear Brakes
The rear 'T' piece is bolted in the centre under the frame above the front diff mount, the rivnut here was a little loose so I tightened it with a spare bolt and a couple of nuts.  I used the same process of offer up, mark, bend, check, move on as I did for the front pipe, starting at 'T' piece and moving towards the alloy block.

Two shorter rigid pipes go from the 'T' piece to some brackets where they meet the flexible hoses.  The brame was drilled and tapped for the 'P' clips.

The pipe route is shown in the pictures below:

From 'T' piece along right hand upper frame rail...


...up frame rail above gearbox...

...final right angle to alloy block.

Right hand side from 'T' piece to flexible hose bracket

Left hand side from 'T' piece loops under fuel pipe, functional but not pretty, will redo this!

Tuesday, 5 April 2016

Pedal Box

The GD manual suggests lining the top of the pedal box up with the lip in the engine bay but I fitted mine about 15mm down, mainly incase my wife ever drives it!

I started by marking a horizontal line with a spirit level where GD recommend then measured down from there. The pedal box was then dissassembled so that I could more easily used the casting to mark the holes. The casting was offered up as far left as possible; making sure enough room was left for the left had nut, and one of lower bolt holes marked.

This first hole was drilled then the casting bolted in place, this allowed any fine tuning of level before the other holes were marked abd drilled. The casting was removed and the remainder of the holes drilled, I didn't have the right size holesaw for the master cylinders so these were cut small and opened out with die grinder.

The pedal box was reassembled and and the brake bias bar installed. I measured between the centres of the master cylinder holes which gave 62mm so the two clevis' were set 62mm apart and equidistant from the pivot. These will be set and locked later,  I'm just not quite sure by who!

Starting with the clutch cylinder the pedal box was bolted in place, the brake cylinders followed. The two brake cylinders are different sizes internally (0.70" and 0.75") so it's worth taking note of which one has been put where.  To get the right pedal height and clearance from the casting about 6mm was trimmed off the end of each brack cylinder thread. I then adjusted the clutch clevis to give a similar position to the brake pedal.

As I'm going to be using an LS engine I will be using the electronic throttle so a modified GM throttle pedal will be installed horizontally on the other side of the bulkhead. I am waiting for the postman to deliver a turnbuckle to finish this but it will mean taking the pedal box off again to drill the brake pedal arm as there's not enough room to get it off in situ.

The manual suggest placing the clutch and brake reservoirs in the engine bay and running hoses down to the master cylinders but to keep the engine bay uncluttered I'll install mine above the master cylinders. The clutch kit comes with two different reservoir sizes and various mounting options, I've placed the smaller one directly on top of the cylinder. I need to make a bracket to fix the brake reservoir to the bulkhead.

GD recommended height of pedal box, mine ended up 15mm lower

Checking level after first two holes drilled

All holes marked reading for drilling 

Pedal box installed

Master cylinders installed 
Safety first!