Sunday, 16 July 2023

Fitting The Parking Brake Cable And Springs

Before the big bolts holding the parking brake units to the bellhousing  are tightened, the parking brake cable should first be fitted. I fitted my calibers when the engine was out of the car - so couldn't do that (see my post HERE). Now the engine was back in, it was cable time.

Compressing the springs can be quite fiddly. Or daunting. Or both. The reason for this is that there are two strong springs that need to be compressed ald located in lugs on the levels: compressing the springs AND locating the cable and springs require more than two hands. And nerves of steel.
 
I'd watched a Youtube video of a DS engine being removed and a very handy valve spring compressor had been used to compress the parking brake springs.
Using a valve spring compressor (image credit Steve Hammond/ BerjFilms)
It wasn't a typical 'G' or 'C' clamp and I couldn't find a valve tool quite like that one. When I removed the springs, I had just used mole grips as they - at least - were adjustable and had a locking action. The problem was, that they simply gripped and tried to compress one side of the spring - meaning it curved and distorted. The mole grips were also heavy and, in laying them down, were prone to slip off the springs. I say 'slip'. What I mean is that the spring maliciously, violently and hell-bent on causing injury, jumped out of the jaws.

So what's the alternative and why didn't I use it? The Citroen manuals  shows a cheap and easy tool for holding the two spings in place while they are correctly located: a collar with two strong split pins to hold the spring in a compressed state.

The idea is the you fit the collars when you are removing the springs and they are already in a compressed state. The holes for the split pins needs to go through the coils of the spring, but are positioned  so that the cable can still be slid out. Do they work?
 
Yes they can do. Here is one in action.
Spring collar in action (photo credit unknown)
You can see that the split pins have to be positioned to leave enough room for the cable - but also need to 'catch' the spring edge. It's a delicate balance and some people had reported that their springs also tore loose - just as mine did with mole grips. To me, they look about as safe as a loose pin in a hand grenade.
 
These days you can buy a tool that compresses the springs quite easily......
The '1577-T' reference above suggests that this tool was originally an official workshop tool made by Fenwick and available to Citroen garages/ dealers, however I've not yet seen it listed in old Fenwick catalogue from back in the day. The manuals are full enough of of photos of other specialised and obscure tools. If this was the workshop tool of choice, why would the workshop manuals include the collar clamp thing instead of these?  They even give measurements and plans for how to make the collar-typre tool.
Measurements for making the simple 'sleeve' tool
 Anyway, here's Adie Pease using the 'proper' tool.
Tool 1577-T in action (image credit Fly-On-The-Wall/ Peacock Productions)
Note how Adie is also having to use mole grips to pull the cable loose of the cleat in the brake arm. That's because there is a second spring on the brake arms on the other side of the car - and so that pulls the cable back even though the first spring is compressed. A plus of this tool is that it has a little metal hook to clamp the handle ends together. and free-up a hand. Another plus is that the business ends of the arms are machined to locate on the spring ends, and the long handles make easy work of compressing the spring. 
Note the jaws of the tool (image credit Fly-On-The-Wall/ Peacock Productions)
 Given the size, these scissor tools are expensive. Especially considering how often you are likely to use them, and for how long they are actually used/ needed.
Given the cost and use I'd get from them, I'd also found (through Googling) that you can buy a tool to compress the door springs of certain General Motors vehicles....
 Here is the principle of how they work. 
I was attracted to it because it held the spring squarely on its ends - which I reasoned would compress it squrely, and significantly  reduce the chance of the DS spring twisting and jumping free. It could be tightened slowly and carefully via the bolt and looked sturdy enough to hold the spring compressed with out any real effort. It even had a notch in it's arms - which could accomodate the cable passing through the spring. This looked to be suitable for the task on a DS parking brake cable. 
 
They were cheap, but at the time they weren't available in the UK. However it still worked out cheaper to buy one of these from the USA than to buy the scissor tool here! here is the one I bought many years ago - way back in 2016(!) - in anticipation of this DS task.
As hoped, the tool is of the right scale to tackle DS parking brake springs. You can see how much the spring is compressed in this photo.
The tool was effective at compressing the spring
I also found that I could replace the tightening bolt with a longer one - meaning the arms could be spread so that they encompassed more of the springs length. The two arms are folded to add strength and that means they hold the springs well. And the notches in the arms leave room for the springs.
The tool will allow for a brake cable through the spring
Fast forward to 2023 and, by chance, Peter Bremner - also baulking at the cost of the proper tool - decided he fancied having a go at making himself a pair of the scissor-type himself. I supplied him with a few photos to help with his design and he set to work. As a 'thank you' he gave me a pair he had made. Here they are.
You can see how much bigger they are than the GM door spring tool I bought.
They are a bit rudamentary - but good enough for the job they need to do. And, importantly, Peter included the recess on each arm to locate over the spring more effectively. And the business ends of the arms are better angled so that they are parallel when closed over a spring and hold it straight - so there is less temptation for it to 'ping' out.
 
 I used the GM Door spring tool and Peters copy of the 'scissor' tool to put my springs on. 
Peter's copy tool in action
Both work, but I think Peter's tool had the edge for simplicity and ease of use. However if you can't make, or afford to buy the scissor tool, the GM tool is a good, cheap option. These days the GM door spring tools I bought is widely (and cheaply) available in the UK. Not sure why!


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