Angular2 Custom HTTP Shell Request fails again

Question

I have a custom HTTP shell written for implementing OAuth2 in Angular2, here is my code:

import { Injectable } from '@angular/core';
import { Http, Headers, Response, Request, BaseRequestOptions, RequestMethod } from '@angular/http';
import { Router } from '@angular/router';
import { Observable } from 'rxjs';
import { API_BASE, AUTH_TOKEN_LS_KEY, CLIENT_ID, CLIENT_PASS, LOCAL_STORAGE_USER_KEY } from 'config/constants';

@Injectable()
export class HttpService 
{
    token: any;

    constructor(private http: Http, private router: Router) {}

    get(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Get);
    }

    post(url:string, body:any):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Post, body);
    }

    put(url:string, body:any):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Put, body);
    }

    patch(url:string, body:any):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Patch, body);
    }

    delete(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Delete);
    }

    head(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Head);
    }

    options(url: string):Observable<Response> {
        return this.request(API_BASE+url, RequestMethod.Options);
    }

    private request(url:string, method:RequestMethod, body?:any):Observable<Response> {
        let headers = new Headers();
        this.createBearerTokenHeader(headers);
        this.createContentTypeHeader(headers);

        let options = new BaseRequestOptions();
        options.headers = headers;
        options.url = url;
        options.method = method;
        options.body = body;

        let requestOptions = {url: url, method: method, body: body};
        let request = new Request(options);
        return this.intercept(this.http.request(request), requestOptions);
    }

    private intercept(observable: Observable<Response>, requestOptions: any): Observable<Response> {
        return observable.catch((err, source) => {
            if( err.status == 401 ) {
                this.refreshToken().subscribe(result => {
                    if( result == true ) {
                        return this.request(requestOptions.url, requestOptions.method, requestOptions.body);
                    } else {
                        localStorage.removeItem(LOCAL_STORAGE_USER_KEY);
                        localStorage.removeItem(AUTH_TOKEN_LS_KEY);
                        this.router.navigate(['/']);
                    }
                });

                return Observable.empty();
            }

            return Observable.throw(err);
        });
    }

    refreshToken(): Observable<boolean> {
        this.token = JSON.parse(localStorage.getItem(AUTH_TOKEN_LS_KEY));
        let refreshToken = this.token.refresh;
        let headers = new Headers();
        this.createBearerTokenHeader(headers);
        return this.http.post(API_BASE+'/auth/default/login', {
                grant_type: "refresh_token",
                refresh_token: refreshToken,
                client_id: CLIENT_ID,
                client_secret: CLIENT_PASS
            }, 
            {headers: headers})
            .map( (response: Response) => {
                let token = response.json();
                if( token ) {
                    this.token = token.access_token;
                    localStorage.setItem(AUTH_TOKEN_LS_KEY, JSON.stringify({"access":this.token, "refresh":token.refresh_token}));
                    return true;
                }

                return false;
            });
    }

    private createBearerTokenHeader(headers) {
        this.token = JSON.parse(localStorage.getItem(AUTH_TOKEN_LS_KEY));
        if( this.token ) {
            headers.append('Authorization', 'Bearer ' + this.token.access);
        }
    }

    private createContentTypeHeader(headers) {
        headers.append('Content-Type', 'application/json; charset=utf-8');
    }
}

Requests go well with appropriate headers. The problem occurs when the access token has expired on the server side and the request for the update token updates perfectly and updates the access token and updates the token in local storage, but I need to send a request that was unsuccessful, and it did not appear again. The error is not displayed, only the update the request for the token passed even the condition of the result is also consistent, but this.request call in the interception method did not occur. What am I doing wrong?